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Photography – Answer Bank

This was made for referential purposes.
This is not official, but made from collaborating questions from multiple textbooks, and even Wikipedia.
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Table of Contents

What is ‘White Balance?’ Establish its relation to ‘Colour Temperature

White balance (WB) is considered as one of the most important settings of a digital camera. Let’s consider a scenario where you want to capture the beauty of sea waves hitting the shore with an overcast sky at the background. Sounds interesting? Well, if you don’t use the correct white balance setting of your digital camera, you may get a picture with colors different from the actual ones. Therefore, in order to produce a beautifully exposed image with true to life colors, you must learn to effectively use the white balance setting of your digital camera.

 

To understand the concept of White Balance, you need to first understand the concept of color temperature. Color temperature is a characteristic of visible light. It provides a method of describing these characteristics and is measured in Kelvin (K). A light having higher color temperature will have more blue light or larger Kelvin value [cool colours] as compared to lower light, which has a smaller Kelvin value [warm colours]. The table shows the color temperature of various sources of light.

You must have noticed some photos turn out with an orange/yellow cast if shot under tungsten lighting or a bluish cast if shot under fluorescent lights. This occurs because each source of light possesses a different color temperature. A digital camera can measure the colors in the red, green, and blue light of the spectrum, as reflected to its sensors. In a photo taken under the midday sun there is the whole spectrum of light (which makes up “white” sunlight). Under these conditions, the colors in an image appear nearest to the “true” colors. An image taken under tungsten bulb (a normal household incandescent bulb) without adjusting the digital camera for white balance produces the dull orange shade as it spreads the biased light. Similarly, an image taken under the fluorescent lighting produces a brighter bluish cast. However, it is possible to shift the color in the desirable direction, provided you have a good understanding of your digital camera and its settings.

All light has a colour and that colour is defined as a temperature. The temperature scale used for light is known as degrees Kelvin. At the lower end of the scale, 2000-4000k, the light is warm, reddish yellows. At around 5500k, the colour is pretty much what we seen at noon on a sunny day. As the scale climbs, the light gets progressively more blue. At about 10,000k we reach the very blue light of a typical flash gun. The Colour Temperature Scale in degrees Kelvin

 

Our cameras have a sensor that determines what the colour of the light is. We typically allow that sensor to automatically select the right white balance by using the auto white balance setting (AWB). For the most part, this sensor is very accurate. But it can be fooled–most commonly by a large block of a single colour. For example, a woman wearing a bright red dress. In this case, the colour sensor will see the image as being more red than it actually is. And it will overcompensate by turning the image more blue. This is often what happens with the sunset pictures. The overabundance of red light fools the camera sensor into adding more blue, effectively neutralizing the scene.

 


 

Why to Adjust the White Balance?

Since different sources of light have different color hues, a picture taken with a normal white balance under artificial lighting conditions transmits the low heat to the camera’s sensor. This light touches the red bits of the spectrum, which results into dull yellow or orange shades in the picture. Though the human eyes can automatically adjust to different lights and color temperatures to sense right color, a camera needs to be adjusted to different lights for accurate color reproduction. By adjusting the white balance setting of your digital camera, you can alter the required light or temperature to produce the most accurate colors in a digital image.

 

Preset White Balance Settings

 

White Balance Settings

Auto – The Auto setting helps in adjusting the white balance automatically according to the different lighting conditions, but you can try other modes to get better results.

 

Tungsten – This mode is used for light under a little bulb like tungsten, and it is often used while shooting indoors. The tungsten setting of the digital camera cools down the color temperature in photos.

 

Fluorescent – This mode is used for getting brighter and warmer shots while compensating for cool shade of fluorescent light.

 

Daylight – This mode is for the normal daylight setting, while shooting outdoors. Many cameras do not have the Daylight mode.

 

Cloudy – This mode is ideal for while shooting on a cloudy day. This is because it warms up the subject and surroundings and allows you to capture better shots.

 

Flash – The flash mode is required when there is inadequate lighting available. This mode helps pick the right White Balance under low light conditions.

 

Shade – A shaded location generally produces cooler or bluer pictures, hence you need to warm up the surroundings while shooting shaded objects.

 

Manual White Balance

You can also adjust your digital camera manually by setting a white object as the reference point. This is done to guide the camera how white the object would look in a particular shot. It is advisable to manually adjust the white balance when taking a picture to compensate for the changing lighting conditions. As the daylight changes during early morning and late evening hours, the varied light intensity is easily perceived by the camera. Therefore, you need to correct the white balance regularly while shooting during these times of the day. To manually set the white balance in your image, you first point your camera at a pure white object, set the exposure and focus. Now, activate the white balance on the object by pressing the button. It may take few seconds for the camera to perceive the shot, but it will this color setting until the next white balance is performed.

 

Conclusion

Some people consider it amateurish to use predetermined settings, when in fact there may be times when we are in a rush and cannot adjust everything manually. Also remember that using these modes will teach you about photography and ideal settings for different conditions. If in doubt, you can use Auto mode, then adjust the settings manually. Auto settings are there to be used so try them all, and become familiar with what each one does.


What are the effect of ‘Aperture’ on ‘Depth of Field.’ What are the other factors that affect ‘Depth of Field?’

A basic definition of depth of field is: the zone of acceptable sharpness within a photo that will appear in focus. In every picture there is a certain area of your image in front of, and behind the subject that will appear in focus.

 

This zone will vary from photo to photo. Some images may have very small zones of focus which is called shallow depth of field. Others may have a very large zone of focus which is called deep depth of field. Three main factors that will affect how you control the depth of field of your images are: aperture (f-stop), distance from the subject to the camera, and focal length of the lens on your camera.

 

Depth of Field

As soon as an object (person, thing) falls out of this range, it begins to lose focus at an accelerating degree the farther out of the zone it falls; e.g. closer to the lens or deeper into the background. With any DOF zone, there is a Point of Optimum focus in which the object is most sharp.

There are two ways to describe the qualities of depth of field – shallow DOF or deep DOF. Shallow is when the included focus range is very narrow, a few inches to several feet. Deep is when the included range is a couple of yards to infinity. In both cases DOF is measured in front of the focus point and behind the focus point.

 

DOF is determined by three factors – aperture size, distance from the lens, and the focal length of the lens. Let’s look at how each one works.

 

Aperture

Manipulating the aperture is the easiest and most often utilized means to adjust Depth of Field.

To achieve a deep, rich and expansive Depth of Field, you’ll want to set the f-stop to around f/11 or higher. You may have seen this principle demonstrated when you look at photos taken outside during the brightest time of the day. In such a case, the camera is typically set at f/16 or higher (that Sunny 16 Rule) and the Depth of Field is quite deep – perhaps several yards in front of and nearly to infinity beyond the exact focus point.

 

Let’s take a look at these two photos as examples. The left side of the photo has an expansive DOF, most likely shot around noon (notice the short, but strong shadows), with an f/22 aperture. The right side of the photo has an extremely shallow DOF; probably an f/2.8 aperture setting. However, to achieve an identical proper exposure, the shutter speed is probably closer to 1/1000th to compensate for the increased amount of light entering the lens at f/2.8.

 

How does aperture control depth of field?

Aperture refers to the access given to light from the lens to the camera sensors. The size of your aperture (the diameter of the hole through which light enters the camera) controls the amount of light entering your lens. Using the aperture (f-stop) of your lens is the simplest way to control your depth of field as you set up your shot.

Large aperture = Small f-number = Shallow (small) depth of field

Small aperture = Larger f-number = Deeper (larger) depth of field

 

It may be easier to remember this simple concept: The lower your f-number, the smaller your depth of field. Likewise, the higher your f-number, the larger your depth of field. For example, using a setting of f/2.8 will produce a very shallow depth of field while f/11 will produce a deeper DoF.

The image on the left was captured at 250th of a second at F5.0 which resulted in a very shallow depth of field,The image on the left was captured at 250th of a second at f/5.0 which resulted in a very shallow depth of field.  

Because of this the background is out of focus allowing the subject to stand out. The image on the right was captured at 1/5th of a second at f/32 which created a deep depth of field and a sharper background.


How does distance control depth of field?

The closer your subject is to the camera, the shallower your depth of field becomes. Therefore, moving further away from your subject will deepen your depth of field.

 

How does the focal length of a lens control depth of field?

Focal Length refers to the capability of a lens to magnify the image of a distant subject. This can get complicated, but the simple answer is that the longer you set your focal length the shallower the depth of field.

 

Example: Your subject is 10 meters (33 feet) away, using a focal length of 50mm at f/4; your depth of field range would be from 7.5 -14.7 meters (24.6-48 feet) for a total DOF of 7.2 meters (23.6 feet). If you zoom into 100mm from the same spot, the depth of field changes to 9.2-10.9m (30.1-35.8′) for a total of 1.7m (5.7′) of depth of field. But if you move to 20m (66′) away from your subject using the 100mm lens, your depth of field is almost the same as it would be at 10 meters using a 50mm lens.

This image of a swan hiding in the tall foliage was captured from about 5m (16′)  with a 300mm focal length lens. This combination of focal length and distance created a depth of field of approximately 5cm (2″).

 

Manipulation of depth of field is a good way to modify the characteristics of your photo, and manipulating the aperture is the ideal way to do this because it has little or no effect on composition. You simply need to change the shutter speed (or change the light sensitivity – ISO) to compensate for the changes in the exposure from the adjustments to the f-number. Changes in distance and focal length also affect DOF, but these changes have trade-offs in terms of composition.

Therefore, changes to aperture are the best way to manipulate DOF without affecting a photo’s composition.


What is ‘Exposure Compensation?’ Describe the occasions where it is applied.

When you use shooting modes other than Manual, the camera will set at least one of the three exposure controls (shutter speed, aperture, and/or ISO) for you. However, your camera provides you with an override called exposure compensation. It gives you the ability to change the camera’s exposure values from something other than what the camera automatically sets for you.

 

So what is exposure compensation?

If you look on your DSLR, you will find a button or menu item with a little + and – on it. This is your exposure compensation button.

Pressing the button will bring up a line graph, labeled with numbers from -2 to +2 (or occasionally -3 to +3), marked at increments of 1/3.

These are your EV (exposure value) numbers. By using these numbers, you are telling the camera to either allow more light in (positive exposure compensation) or allow less light in (negative exposure compensation).

 

To put it simply, it allows you to incrementally adjust the camera’s exposure around the default reading that meter is giving. Nearly all DSLR’s and advanced compacts have this feature to some extent. Some are limited to changes of ½ a stop or 1 complete stop at a time, professional level cameras will allow you to define the amount of compensation from 1/3 of a stop to 1 stop and make changes of up to 5 stops either way.

 

Your camera’s light meter has given you a reading of 1/125 (shutter speed) at f/5.6 (aperture). If you then dial in an exposure compensation of +1EV, the meter would open up the aperture by one stop to f/4. This means that you are effectively dialing in an over-exposure and creating a brighter image. The situation would be reversed if you dialed in a negative EV number.

 

How does it work?

 

Well let’s assume you are shooting in aperture priority. You have chosen your aperture based on the subject matter but find that your image is constantly dark. By adding +1/2 or +1 stops via the exposure compensation on your camera you will lighten the image overall.  When in aperture priority, because you want the aperture to remain the same, the camera will use a slower shutter speed to compensate.

 

Conversely in shutter priority mode, the camera will open the aperture, allowing more light to reach the sensor (or film). The reverse is true if you are finding your image is too light, dialing in a minus exposure compensation number will darken your image incrementally.

 

This balance of light and dark is usually evaluated based on the entire frame that you see either in the camera’s viewfinder or the LCD.  Some cameras offer different ways to evaluate the scene (metering modes), such as “spot” or “center-weighted.” These are very helpful in many situations; however, we will revisit these concepts later.

 

Exposure compensation allows you to increase or decrease the exposure of a scene.  Essentially, you are telling the camera, “I see what you’re doing there with your ‘balanced’ exposure, but I want it to be brighter (or darker),” as the case may be.

 

Exposure compensation is generally adjustable in 1/3 or 1/2 EV or “stops.”  Each full “stop” adjustment either doubles or halves the amount of light reaching the image sensor depending on whether it is a +1 or -1 adjustment.

 

Accordingly, an exposure compensation adjustment of +1 EV will result in an image that is twice as bright as the base exposure.  Likewise, an exposure compensation adjustment of -1 EV will result in an image that is half as bright as the base exposure.

 

When to Use Exposure Compensation

Standard Camera Metering in Aperture Priority Mode
Note the camera exposed the scene for the window in order to average the dark and light portions of the image. Because the window is very bright, the subject turned out dark.

 

One of the common times to use exposure compensation is when your main subject is brighter or darker than your entire metered scene. This occurs often when you have a backlit subject (e.g., subject in the shade with full sun scene or window in background) or when your subject has a lot of light on them, but the rest of the scene is dark (e.g., a wider shot of a band/singer in a concert).

 

In some cases, it may be better to switch to manual mode, and a lot of photographers would prefer this anyway. However, there are many cases where photographers are more comfortable with a camera-metered scene or where it’s simply quicker to hit a +1 or -1 on the exposure compensation dial, get the shot and be done with it.

Adding +2 EV via the exposure compensation dial to the same scene shown above, the camera exposed the scene 2 full stops brighter than it metered the scene at. As a result, you can make out the subject’s face. While we could use a little more compensation (or perhaps some fill flash), we are getting closer to exposing for the subject rather than the window (or overall scene).

To further demonstrate how far off camera metering can be, this is post-processed version of the +2 EV image above. I added an additional +1.4 EV boost to the exposure in Lightroom to get the image close to a proper exposure for the subject. So, the camera actually underexposed the subject by 3.4 stops in metering this scene.

 

If your subject is backlit, the camera is going to meter that backlight and make your subject darker in order the “level” that scene out at 18% gray. This can be corrected by increasing the exposure compensation, by telling the camera that this scene should be +1/3 EV, +1 EV or +2 EV brighter than what it “thinks.”

 

It is the same thing for bright subjects in dark areas. Get the exposure right for the subject and let the background be as dark as it needs to be. If your subject is blown out to white, then the picture isn’t worth taking. Dial the exposure compensation down by -1 EV or whatever looks right to you for the subject.


Discuss Pixel & Resolution. Establish its relation with Image magnification.

Pixel and resolution are two important concepts that are used together in photography. Both are usually used when referring to camera and printer settings. Though these terms are used simultaneously and one concept plays a greater part in the other; they differ from each other in various ways.

What is a Pixel

The word “pixel” means a picture element. Every photograph, in digital form, is made up of pixels. They are the smallest unit of information that makes up a picture. Usually round or square, they are typically arranged in a 2-dimensional grid.  In the image below, one portion has been magnified many times over so that you can see its individual composition in pixels. As you can see, the pixels approximate the actual image. The more pixels you have, the more closely the image resembles the original.

Pixels are a basic measuring unit in computer imagery. They collectively create images that one can see on a digital screen display. Resolution is the term that is used to describe the crispness and detail of an image. In optics, it is most commonly described as the ability of an imaging system to resolve detail in the object that is being imaged.

Pix-el is basically a mixture of ‘Picture’ and ‘Element’. Pixels collectively create images that one can see on a digital screen display. Generally, the higher the pixel counts within a digital image, the sharper the image. A digital camera usually produces better images because they produce a higher pixel count. It makes the image more suitable for enlargements and allows more possibility for image cropping. Pixels are a basic measuring unit in computer imagery. It is used in cameras, screens, TVs, etc., anywhere an image is displayed. It is also considered as a physical point in a raster image or the smallest element that is displayed in an image. An image is often made up of small pixels that come together to form a bigger picture. Pixels can also be used as color dots to create a whole image, where pixels represent colors in the image.

 

Notice when an image is magnified to its full extent, it shows tiny squares that make up the picture. These are pixels; these pixels together make up the image that is being displayed. Screens and TVs that are available these days come with a fixed pixel amount, which is given under resolutions. This determines the quality of the image that would be available on the screen. The higher the resolution, the higher the pixel count, which results in a better image.

 

Resolution

The number of pixels in an image is sometimes called the resolution, even though this is a bit of a misuse of the term. If we are using the term to describe pixel count, one convention is to express resolution as the width by the height, for example a monitor resolution of 1280×1024. This means there are 1280 pixels from one side to the other, and 1024 from top to bottom.

 

Another convention is to express the number of pixels as a single number, like a 5 megapixel camera (a megapixel is a million pixels). This means the pixels along the width multiplied by the pixels along the height of the image taken by the camera equals 5 million pixels. In the case of our 1280×1024 monitors, it could also be expressed as 1280 x 1024 = 1,310,720, or 1.31 megapixels.

 

 

 

 

 

Dictionary.com defines ‘Resolution’ as:

  • The process or capability of making distinguishable the individual parts of an object, closely adjacent optical images, or sources of light
  • A measure of the sharpness of an image or of the fineness with which a device (as a video display, printer, or scanner) can produce or record such an image usually expressed as the total number or density of pixels in the image <a resolution of 1200 dots per inch>
  • In Physics & Chemistry: The act or process of separating or reducing something into its constituent parts: the prismatic resolution of sunlight into its spectral colors.
  • The fineness of detail that can be distinguished in an image, as on a video display terminal.

 

The amount of detail that the camera can capture is called resolution. It is determined by the dimension of the unit of information representing an image. In optics, resolution is the ability to distinguish two separate objects. The resolution of a system is based on the minimum distance at which the two objects can be separated and distinguished as individuals. The resolution depends on the aperture of the instrument and the wavelength of the observed light. The resolution of digital images can be described in many ways including pixel resolution, spatial resolution, spectral resolution, temporal resolution and radiometric resolution.

 

Resolution can be measured in 3 ways:

  • Sample per inch (spi, scanners)
  • Pixel per inch (ppi, monitors)
  • Dots per inch (dpi, printers)

Discuss on Quality of Light.

As in most things quantity is how much or how many, and quality is how good it is. So how do you measure whether the light is good or not?

 

The simplest definition of quality of light is,
Quality of light is defined by the size of the light source relative to the subject.

 

What that means in real terms is that if you have a small light source it will produce hard lighting. If you have a large light source the light will be soft, however, it is also affected by the distance of the light source to the subject. If the large light source is close to the subject, it is proportionally large compared to their face. But if you move it back away from the subject quite a distance it changes the relative size of the light.

 

Hard and Soft Light are different types of lighting that are commonly used in photography and filmmaking. Soft light refers to light that tends to “wrap” around objects, casting diffuse shadows with soft edges. Soft light is when a light source is large relative to the subject; hard light is when the light source is small relative to the subject.

 

The hardness or softness of light depends mostly on the following two factors:

  • Distance The closer the light source, the softer it becomes.
  • Size of light source The larger the source, the softer it becomes.

 

The softness of a light source can also be determined by the angle between the illuminated object and the ‘length’ of the light source (the longest dimension that is perpendicular to the object being lit). The larger this angle is, the softer the light source.

 

Hard Light

Hard light is usually very directional and, due to this fact, the shadows that are created by it are very hard-edged. There are very few mid tone values separating the highlights from the shadows. Hard light is characterized by strong, well defined shadows and a high degree of contrast. With hard light you will notice deep, dark shadows, and bright, sometimes overblown highlights or whites. People photographed in hard light will often squint and have harsh unflattering shadows on their face.

 

Hard light sources cast shadows whose appearance of the shadow depends on the lighting instrument. For example, fresnel lights can be focused such that their shadows can be “cut” with crisp shadows. That is, the shadows produced will have ‘harder’ edges with less transition between illumination and shadow. The focused light will produce harder-edged shadows. Focusing a fresnel makes the rays of emitted light more parallel. The parallelism of these rays determines the quality of the shadows. For shadows with no transitional edge/gradient, a point light source is required. Hard light casts strong, well defined shadows.

 

When hitting a textured surface at an angle, hard light will accentuate the textures and details in an object

This little girl is here to put a smile on yer face, with soome hard light

DROP IT FAM

 

And here are few other baddies in Hard Light

Soft Light

Soft light then is the opposite of hard and is characterized by soft or not easily defined shadows, and low contrast. In soft light you may not even be able to distinguish where the shadows fall or if there is any. People photographed in soft light have less shadows and do not have to squint.

 

Soft light is that which casts either no shadows, or shadows with soft edges. It is more suitable than hard light for many subjects, including many types of landscape and portraits (but especially portraits).

 

For example, if you are taking someone’s portrait during the middle of a sunny day, then one of the best things you can do is find some shade, and take a photo of your model there. The softness of the light, and the fill from the brighter, sunlit surroundings, is a very flattering type of light that makes the model’s face glow and creates large catchlights in her eye.

 

Soft light use is popular in cinematography and film for a number of different reasons:

  • Cast shadow-less light.
  • Fill lighting. Soft light can reduce shadows without creating additional shadows.
  • Make a subject appear more beautiful or youthful through making wrinkles less visible.
  • Supplement the lighting from practicals. This technique is used to perform “motivated” lighting, where all light in the scene appears to come from practical light sources in the scene. Soft light does not cast shadows that would be a giveaway of a supplementary light source.

Princess Zelda

This is Zelda. In Soft Light.
The Green Kid is Link

This little girl is back to put a smile on yer face, with soome soff light
DROP IT FAM!!

 


Photography Lighting Modifiers

The smaller the light source, the harsher the shadows and contrasts will be. Take the Sun on a clear day, for example. Though the Sun is huge in reality, it’s a small, bright light source shining on the much larger Earth. Consequently, when you look at your object, you’ll see strong contrast and dark shadows and harsh edges.

When the clouds roll in, look at the shadows again: They’ve softened and have more attractive, gentle feathering at the edges. Contrast has also been reduced. The clouds have scattered the light rays, diffusing and softening the light. Note that the clouds have effectively increased the size of the light source relative to the subject.

 

Softer light is generally a desired effect when working with all subjects, from people to highly reflective objects like jewelry, which is my specialty. The specular highlight– the bright spot on an object–is usually more pleasant when created by soft lights.

 

As photographers, we collect light with our cameras. Sometimes, the universe cooperates and gives us the perfect window on an overcast day, producing light in which its impossible to take a bad photo. For every other scenario, however, we’re on our own. Luckily, there are many tools out there that can help us create the exact light we want in just about any situation.

 

Consider this an introduction to some of the most well-known and versatile lighting modifiers available. With these in your arsenal, you can bend light to your will and make your photos look just how you want with a little creativity and probably a little gaffer’s tape along the way as well.

 

Umbrellas

Similar to rain umbrellas, but without the handle, umbrella modifiers are very affordable and are found in most studios. Theycome in several sizes and varieties: black outside with white or silver interiors, all white (called shoot-thru), and specialized ones with gold or zebra patterns (white-silver-white-silver) on the interior.

 

The basic concept is that when a light is pointed at the center of the umbrella, the light rays are reflected back and scattered or diffused. Umbrellas are the ultimate in portability and speedy setup. Common for people photography, they’re great for group coverage when two are used.

In the product photography studio however, the umbrella generally isn’t your best choice. The inherent problem is light spill—lack of control over the light. Since the diffused light spreads out over a large surface, you would need to use “flags” or black cards to block the light from certain areas of your image.

 

A deeper umbrella will produce a tighter, more focused beam that’s very intense at the center and falls off more quickly. A more shallow umbrella will throw a wider beam of light that has a more feathered appearance at the edges.

 

The color and finish of the reflective lining can also make a big difference in the look of the reflected light. A shiny, gold interior, for instance, will produce light that’s relatively hard in appearance and warm in color. A matte, white reflective umbrella, however, will produce a softer, more neutral light.

 

Softboxes

Softboxes produce soft controlled directional light. As stated in the beginning, the larger the light source appears to the subject, the softer and more diffused the light becomes.

Softer light is generally a desired effect when working with all subjects, from people to highly reflective objects like jewelry, which is my specialty. The specular highlight– the bright spot on an object–is usually more pleasant when created by soft lights.

 

These light modifiers are the workhorses in our studio. Softboxes work similarly to umbrellas by scattering and softening the light, but in quite a different manner. They are rectangular boxes made of opaque, black material on the outside, lined with diffusion material on the inside (white or silver), and usually have an additional white diffusion panel called a baffle, which sits several inches away from light. The front of the softbox is open but kept covered with one more layer of white diffusion material. This produces a very soft light source and, because of the design, light is directional and therefore controlled. Should a photographer need additional control, most good brands have a grid that can be fastened with Velcro at the front. Softboxes produce a rectangular catchlight on the subject.

 

On the negative side, softboxes are big and bulky. For onsite shoots, you’ll have to take them apart, unless you have a minivan or SUV. Some brands are easier than other to assemble, but generally they’re a pain in the neck and since time is money, might not be worth the effort.

 

They cost substantially more than umbrellas and can strain a beginner’s budget, depending on the brand and size. Softboxes come in many shapes and sizes, ranging from small ones that can be mounted on camera flash guns to enormous ones used to illuminate cars and trucks.

Octoboxes

They are basically the same as a softbox except they have eight sides rather than four They are very popular in fashion and portrait photography. Quite large, they can be unwieldy, measuring from five to seven feet. The catch light they produce is similar to the umbrella’, multi-sided and octagonal.

 

The difference, however, will be in the quality of light; smaller octoboxes create a more direct light, while larger octoboxes result in a softer, more subtle wrap-around light. Larger octoboxes result in almost no shadow around your subject, while smaller octoboxes are more directional and can start leaving a shadow with the smaller-sized octoboxes. You should also be aware that the larger the octobox you’re using, the stronger the flash that will be needed to radiate onto your subject for optimal results.

 

Beauty Dishes

It looks a bit like a big salad bowl, but this metal dish is a standard piece of kit for many portrait photographers. They’re especially common on fashion sets where makeup is a key piece of the portrait equation.

 

A very simple device, a beauty dish looks like a bowl that fits onto your light with a small plate that reflects the light back onto the sides of the dish. It produces a light that is in between a bare studio light and a softbox: the shadow/highlight transition is more abrupt, giving it higher contrast.

 

Because of this, the beauty dish tends accentuate flaws in your model’s skin, so attention must be given when placing the light. It works best between three and four feet from the model, giving what many call a “liquid wrap-around lighting.” The beauty dish produces a circular catchlight.

 

A standard beauty dish uses a center plate to reflect light back toward the dish. The light then reflects off of the sides of the dish and hits the subject. The sharp edge of a beauty dish can be used to produce unique shadows on your subject but the lighting itself is very similar to a medium softbox with the front diffusion panel removed.  Adding a “sock” to the front of a beauty dish makes it “softer” and even more similar to a standard softbox.

 

AND THE MOST IMPORTANT ONE

Color Gels

A color gel is a transparent, colored sheet placed in front of a light or used in combination with other modifiers such as a grid. Used extensively in all areas of studio work, color gels give depth, dimension, and a mood to images. Available in just about every color on the spectrum, they are an essential part of a functioning studio. They’re also cheap, so have fun experimenting.

 

The shape and intensity of your light is crucial, but the color can also make a huge difference. You can tweak the color of your light using translucent, tinted sheets that come in just about any tone you can imagine.

 

You’re probably already familiar with the concept of color temperature, but in case you’re not, here’s a little refresher. Different temperatures of light appear as different colors to our eyes and, even more so, to our cameras. Things like incandescent lights look more orange or yellow, while sunlight and most camera flashes are hotter and look like true “white.” Adding a gel to the light source can help correct it to be more white, or go in the other direction and introduce a dramatic splash of color. The below images will give you a clearer understanding of color gels.

This concludes my low effort shitposting.


Explain the term ‘Three point lighting.’

Three-point lighting is a technique widely used in traditional photography and cinematography. Its purpose is to properly illuminate a subject in an effective way that is not only pleasing to the eyes but also relatively simple in its approach. By using three separate lights you have complete control on how the subject is illuminated.

 

Three-point lighting is great for creating a studio type lighting effect, if you are creating a still image or if you need to illuminate a single subject or product. Three-Point-Lighting The most common way to achieve proper three-point lighting is by using three different spot lights in the scene. Setting up each light the correct way will allow the subject to be illuminated without deep shadows and be seen properly in the camera view.

 

Three point lighting is fundamentally a way of expressing where to place your lights for cinematography and photography. By using these three main types of lighting, the main subject in a scene can be properly illuminated and highlighted.  

 

Key Light

Gives light to the Object/Fake Candid

 

The first and most important light is the key light. Like the name suggests[it does not suggest shit], this light is vital when establishing the overall lighting for the scene. It should highlight the form and dimension of the subject. Typically it is placed to the right of the camera at a 45 degree angle. [dont be confused. Works fine either ways. The next line is a killer]

 

While this works most of the time, it really depends on your scene and what you need to illuminate. Play with different angles and positions until you are happy with the result. Remember, most of your light will be emitted from the key light so a higher intensity may be needed.

 

This light focuses on the main person or object in the scene. This typically illuminates the person or object, reducing shadows and making the subject stand out among other people, objects, or environment.

 

The key light is typically implemented first, as it is the most direct source of light that will be illuminating the main subject of the scene. Fill lighting and back lighting are very important, but they mostly supplement the key lighting.

I searched for KRK Pics, but weren’t available. Deal with this.

 

Fill Light

Takes care of the shadows

 

Sometimes the key lighting does create shadows, and these must be eliminated in order to make the subject clearly stand out. Fill lighting is used to “fill in” all dark areas.

 

The fill lights are installed once the key lights have been placed. There will likely still be some areas of darkness and shadow from the key lighting, so the fill lights must be used to illuminate these dark areas.

 

When placing fill lights, you should ensure that they are not too strong or too light. If the fill lighting is too strong, it can actually create its own shadows, which is the very problem that fill lights are supposed to resolve. If it is too light, it may not properly fill all of the shadowed areas.

There are several ways to diminish the light if it is too strong. Depending on the type of lighting being used, it may be able to be dimmed using dimmers. If not, the light can be moved away from the subject. Filters and neutral density gels can also be used to effectively reduce the lighting.

 

Back Lighting

Light from Back. Thats it

This light provides a direct contrast between a specified person or object and the background environment.

 

As the name implies, backlighting is placed behind the main subject. If there’s not enough contrast, or if the subject blends in too much with the environment, the back lighting is used to illuminate the silhouette of the subject in order to make it stand out. The camera responds well to this light by practically taking the subject away from the environment and background, and making the entire scene focus directly on that subject.

 

Dimmers can be used to effectively control the back lighting. As with key and fill lights, filters and neutral density gels can be used to reduce the backlight if necessary. Placing the lights at different heights provides a variety of enhancements as well. Just be sure that light does not accidentally flash directly toward the camera as this can be distracting, and can cause problems with the video.

The goal of three point lighting is to create the illusion of a three-dimensional subject in a two-dimensional image. While you can create dimension a number of different ways, there’s no doubt that using light and shadow is a powerful way to accomplish this, and three point lighting is the lighting technique most commonly used.

 

Three-point lighting is a standard method used in visual media such as theatre, video, film, still photography and computer-generated imagery. By using three separate positions, the photographer can illuminate the shot’s subject (such as a person) however desired, while also controlling (or eliminating entirely) the shading and shadows produced by direct lighting.


Describe Rembrandt, Butterfly, Short, Broad, Low key, and Split lighting with Rough Diagram.

 

Split Lighting

Split lighting is exactly as the name implies – it splits the face exactly into equal halves with one side being in the light, and the other in shadow. It is often used to create dramatic images for things such as a portrait of a musician or an artist. Split lighting tends to be a more masculine pattern and as such is usually more appropriate or applicable on men than it is for women.

 

Split lighting involves “splitting” the face into two proportional halves, with one side being in the shadow and the other side being in the light. It can be done with a single light source, which makes it easy and inexpensive to execute even for beginners.

The light contained in the shadow side of your subject—particularly his eye—is called the catchlight. This adds to the impact of the image and draws the audience to it.This lighting technique is ideal for a variety of purposes:

 

  • Achieving a dramatic effect in portraits
  • Fashion photography
  • Commercial photography
  • Adding variety to a set of themed portrait photos
  • Making a broad face look slimmer

 

To achieve split lighting simply put the light source 90 degrees to the left or right of the subject, and possibly even slightly behind their head. Where you place the light in relation to the subject will depend on the person’s face. Watch how the light falls on them and adjust accordingly. In true split lighting, the eye on the shadow side of the face does pick up light in the eye only. If by rotating their face a bit more light falls on their cheek, it’s possible their face just isn’t ideal for split lighting.

Loop Lighting

Some brave men call this as shembud lighting

Loop lighting is made by creating a small shadow of the subjects noses on their cheeks. To create loop lighting, the light source must be slightly higher than eye level and about 30-45 degrees from the camera (depends on the person, you have to learn how to read people’s faces).

 

Loop lighting is one of the most popular lighting techniques due to its simplicity and suitability to almost all types of subject. The name ‘loop’ comes from the appearance of the shadow this type of lighting creates under the subject’s nose, shaped like a loop. This shadow does not appear directly under the nose, but slightly on its side, extending toward the side of the face, and it can be either small and contained or stretching all the way down to the corner of the mouth.

It is important in this technique that the loop shadow does not touch any possible shadow appearing on the cheek. This setup allows light on most of the face, but at the same time creates a sense of depth through its shadows, generating a very versatile but not flat-looking lighting, suitable for most projects and purposes.

To achieve, place your key light slightly to the side of the subject so the shadow under the nose becomes a small loop. Butterfly lighting can easily be transformed into loop lighting by lowering the light and slightly moving it over.

 

This type of light works best with average, oval-shaped faces.  The loop shadow will never merge with the shadow on a cheek. This creates a new lighting technique called “Rembrandt Lighting.”

Rembrandt lighting

Rembrandt lighting is a lighting technique that is used in studio portrait photography. It can be achieved using one light and a reflector, or two lights, and is popular because it is capable of producing images which appear both natural and compelling with a minimum of equipment. Rembrandt lighting is characterized by an illuminated triangle under the eye of the subject on the less illuminated side of the face. It is named for the Dutch painter Rembrandt, who often used this type of lighting.

 

Unlike loop lighting where the shadow of the nose and cheek do not touch, in Rembrandt lighting they do meet which, creates that trapped little triangle of light in the middle. To create proper Rembrandt lighting make sure the eye on the shadow side of the face has light in it and has a catch light, otherwise the eye will be “dead” and not have a nice sparkle. Rembrandt lighting is more dramatic, so like split lighting it creates more mood and a darker feel to your image.

 

 

To create a small triangle of highlight on the shadowy cheek, place the key light farther to the side of the subject than it is in the loop lighting scenario.  The light is going to almost be coming off a bit to the side of the subject and slightly above eye level (however, this depends on how their head is placed.)

 

You may have to play around and move the light closer to the subject in order to get a nice, strong Rembrandt light.  This is a highly flattering lighting technique that can be used on almost anyone!

Butterfly Lighting

 

Butterfly lighting is aptly named for the butterfly shaped shadow that is created under the nose by placing the main light source above and directly behind the camera. The photographer is basically shooting underneath the light source for this pattern. It is most often used for glamour style shots and to create shadows under the cheeks and chin. It is also flattering for older subjects as it emphasizes wrinkles less than side lighting.

Very small over here. But Yes

 

 

To achieve this type of lighting, place the light high and directly in front of the face.  (Because the light is directly in line with the face, it works best when putting your light on a boom.)  Butterfly light is typically a more feminine lighting and when used properly, it will accentuate high cheekbones.  

 

Be cautious of subjects with hallow or deep eye sockets – when the light is placed high, if your subject has deep eye sockets there will be no light in their eyes.

Broad Lighting

 

Broad lighting is not so much a particular pattern, but a style of lighting. Any of the following patterns of light can be either broad or short: loop, Rembrandt, split.

 

Broad lighting is when the subject’s face is slightly turned away from centre, and the side of the face which is toward the camera (is broader) is in the light. This produces a larger area of light on the face, and a shadow side which appears smaller. Broad lighting is sometimes used for “high key” portraits. This type of lighting makes a person’s face look broader or wider (hence the name) and can be used on someone with a very slim face to widen it. Most people however want to look slimmer, not wider so this type of lighting would not be appropriate for someone who is heavier or round faced.

Broad lighting will create a “broad” or “wide” face.  This is because the part of the face that is lit (the part of the face that is facing the camera) is wider than the section of the face that is in shadow.  Don’t use this type of light on heavier people, it will make them look bigger than they are. It’s ideal for thin people.

To achieve this, place the light opposite the direction of your subject’s face.  For example, If the subject is looking to the left ofthe camera, place the light to the right of the camera.

Short Lighting

Short lighting is the opposite of broad lighting. As you can see by the example here, short lighting puts the side turned towards the camera (that which appears larger) in more shadow. It is often used for low key, or darker portraits. It puts more of the face in shadow, is more sculpting, add 3D qualities, and is slimming and flattering for most people.

Short lighting will create a narrower looking face.  This is because the part of the face that is in shadow (the part of the face that is facing the camera) is wider than the section of the face that is lit.  This type of light is great for heavier people! It creates a thinning effect which makes it really flattering lighting.

To achieve this, place the light in the same the direction of your subject’s face. For example, If the subject is looking to the left of the camera, place the light to the left of the camera.

Lowkey Lighting

Low-key lighting is a style of lighting for photography, film or television. It is a necessary element in creating a chiaroscuro effect[treatment of light and shades in drawings and paintings].

Traditional photographic lighting, three-point lighting uses a key light, a fill light and a back light for illumination. Low-key lighting often uses only a key light, optionally controlled with a fill light or a simple reflector.

Low key light accentuates the contours of the subject by throwing areas into shade while a fill light or reflector may illuminate the shadow areas to control contrast. The relative strength of key-to-fill, known as the lighting ratio, can be measured using a light meter. Low key lighting has a higher lighting ratio, e.g., 8:1, than high-key lighting, which can approach 1:1.

The term “low key” is used in cinematography and photography to refer to any scene with a high lighting ratio, especially if there is a predominance of shadowy areas. It tends to heighten the sense of alienation felt by the viewer, hence is commonly used in film noir and horror genres. In film, low-key lighting is associated with German Expressionism and later film noir.

 


What is composition? Discuss any three rules of composition. Support your answer with diagrams.

The term “composition” applies not only to visual arts, but to music, dance, literature and virtually any other kind of art. In certain contexts, such as writing, this term may not be as widely used, but is just as valid nonetheless. In general, the term “composition” has two distinctive, yet related meanings.

 

First and foremost, “composition” describes placement of relative objects and elements in a work of art. Consequently, composition is a key aspect of a good work of art. There is hardly a way to overemphasize the importance of composition. Any aspiring artist ought to give composition of his work a lot of attention. A good composition is one that has just enough detail. Too few elements is bad because it robs the work of art of necessary detail that makes correct interpretation possible. It also ruins the balance of an image. And too many elements can be very distracting as well. Good composition requires good balance. It is best to make sure all the elements present are necessary for the idea or story you are trying to pass on.

 

In some cases, composition can mean the work of art itself and is a synonymous to that term. For example, when talking about a specific installation or dance, a phrase “This composition…” can be used. Such a definition also widely applies to music (creators of which are known as composers) and paintings.

 

There are no fixed rules in photography, but there are guidelines which can often help you to enhance the impact of your photos. These guidelines will help you take more compelling photographs, lending them a natural balance, drawing attention to the important parts of the scene, or leading the viewer’s eye through the image.

 

Rule of Thirds

 

Imagine that your image is divided into 9 equal segments by 2 vertical and 2 horizontal lines. The rule of thirds says that you should position the most important elements in your scene along these lines, or at the points where they intersect.

 

Doing so will add balance and interest to your photo. Some cameras even offer an option to superimpose a rule of thirds grid over the LCD screen, making it even easier to use.

Balancing Elements

Placing your main subject off-centre, as with the rule of thirds, creates a more interesting photo, but it can leave a void in the scene which can make it feel empty. You should balance the “weight” of your subject by including another object of lesser importance to fill the space.

Leading Lines

 

When we look at a photo our eye is naturally drawn along lines. By thinking about how you place lines in your composition, you can affect the way we view the image, pulling us into the picture, towards the subject, or on a journey “through” the scene. There are many different types of line – straight, diagonal, curvy, zigzag, radial etc – and each can be used to enhance our photo’s composition.

Symmetry and Patterns

We are surrounded by symmetry and patterns, both natural and man-made., They can make for very eye-catching compositions, particularly in situations where they are not expected. Another great way to use them is to break the symmetry or pattern in some way, introducing tension and a focal point to the scene.

Viewpoint

Before photographing your subject, take time to think about where you will shoot it from. Our viewpoint has a massive impact on the composition of our photo, and as a result it can greatly affect the message that the shot conveys. Rather than just shooting from eye level, consider photographing from high above, down at ground level, from the side, from the back, from a long way away, from very close up, and so on.

Background

How many times have you taken what you thought would be a great shot, only to find that the final image lacks impact because the subject blends into a busy background? The human eye is excellent at distinguishing between different elements in a scene, whereas a camera has a tendency to flatten the foreground and background, and this can often ruin an otherwise great photo. Thankfully this problem is usually easy to overcome at the time of shooting – look around for a plain and unobtrusive background and compose your shot so that it doesn’t distract or detract from the subject.

Depth

Because photography is a two-dimensional medium, we have to choose our composition carefully to conveys the sense of depth that was present in the actual scene. You can create depth in a photo by including objects in the foreground, middle ground and background. Another useful composition technique is overlapping, where you deliberately partially obscure one object with another. The human eye naturally recognises these layers and mentally separates them out, creating an image with more depth.

Framing

The world is full of objects which make perfect natural frames, such as trees, archways and holes. By placing these around the edge of the composition you help to isolate the main subject from the outside world. The result is a more focused image which draws your eye naturally to the main point of interest.

Cropping

 

Often a photo will lack impact because the main subject is so small it becomes lost among the clutter of its surroundings. By cropping tight around the subject you eliminate the background “noise”, ensuring the subject gets the viewer’s undivided attention.

Cut out all unnecessary details to keep keep the viewer’s attention focused on the subject.

 

Experimentation

With the dawn of the digital age in photography we no longer have to worry about film processing costs or running out of shots. As a result, experimenting with our photos’ composition has become a real possibility; we can fire off tons of shots and delete the unwanted ones later at absolutely no extra cost. Take advantage of this fact and experiment with your composition – you never know whether an idea will work until you try it.

Negative Space

 

Negative space is the space surrounding the main subject in an image.  The space in the image is just as important as the subject itself because it gives the subject “breathing room” and can set the mood or convey an emotion. Negative space helps eliminate distracting elements in an image and gives the subject space to “move” when motion is involved.

On that note, if the subject is looking away from the camera, it’s helpful to have them looking into the negative space, rather than away from the space. Look at the photo below.

 

Rule of Odds

The eyes are drawn to images that contain an odd number of elements rather than those with an even number. At least that’s the theory behind the rule of odds. Additionally, it states the human eye is also naturally drawn to the center of a group. If there are only two objects in an image, the eye will fall between the two objects. If you want an element of your images to stand out, place it between the other two objects, the eye naturally lands on it instead of empty space.

This seems like a simple enough concept when working with objects you can manipulate, but finding natural elements that meet the rule of odds can be slightly more challenging. Fortunately, the more time you spend looking for these occurrences, the easier it will to spot them!

 

Patterns

Patterns are all around us, both in nature and in mad-made structures. Using patterns in your images creates a sense of rhythm and harmony. Patterns appear when elements such as lines, shapes, colors, or forms repeat themselves. The secret to finding patterns is to look at your subject and image from different angles and viewpoints. The patterns seen in the colorful umbrellas lined up on a beach may not be as obvious when viewed from ground level, but are much more obvious when viewed from your hotel balcony. Move your feet, mix it up a little!

You can also find patterns by looking more closely at subjects. Macro images showcase patterns in nature that are not otherwise noticed. Light patterns can also make for interesting images, such as the way the sunlight shines through the pillars lining a walkway. Once you start noticing all the patterns that surround you, it will be hard to see anything else.

 

Color Theory

Do you remember the days of selective color editing? When an image was converted to black and white, but one element was left in color. While the editing technique may be dated, the idea of using color in composition to draw attention to a main element is still in use.

The use of color can drastically change the mood of your image. The use of cooler colors (blues, greens, and purples) create a calm and tranquil mood. Warmer colors such as reds, oranges, and yellows create an energetic or happy mood.

 

Colors can also be used to draw attention to one main element. Adding a pop of color to a de-saturated or monochromatic background creates a strong focal point. Take notice of the colors in the world around you. Notice how different colors make you feel then incorporate those into your photographs.

fin

Composition in photography is far from a science, and as a result all of the “rules” above should be taken with a pinch of salt. If they don’t work in your scene, ignore them; if you find a great composition that contradicts them, then go ahead and shoot it anyway. But they can often prove to be spot on, and are worth at least considering whenever you are out and about with your camera.


Define synchronization. Discuss all the possible uses of Slow Sync.

I am really confused if Flash Sync, and Sync are same. I am considering Flash Sync. If answer is Wrong. Revert.

Any two or more incidents happening simultaneously can be called Synchronized actions or Synchronization. In Photography, the term synchronization is referred to as coupling of flash and the shutter movement. Synchronization is coordination between the opening of the shutter to take a picture and the firing of flash light to illuminate the scene. Flash synchronization is defined as synchronizing the firing of a photographic flash with the opening of the shutter admitting light to photographic film or electronic image sensor. It is often shortened to flash sync or flash synch.

 

In cameras with mechanical (clockwork) shutters synchronization is supported by an electrical contact within the shutter mechanism, which closes the circuit at the appropriate moment in the shutter opening process. In electronic digital cameras, the mechanism is usually a programmable electronic timing circuit, which may, in some cameras, take input from a mechanical shutter contact. The flash is connected electrically to the camera either by a cable with a standardised coaxial PC (for Prontor/Compur) 3.5 mm (1/8″) connector (as defined in ISO 519  ), or via contacts in an accessory mount (hot shoe) bracket.

 

In a camera, flash synchronization is defined as synchronizing the firing of a photographic flash with the opening of the shutter admitting light to photographic film or electronic image sensor. It is often shortened to flash sync or flash synch.

 

Flash Sync Mode, including Rear Curtain. Cameras typically offer a few flash sync modes. The “curtains” below refer to the focal plane shutter, which has a front curtain which opens to expose the sensor to light, and a rear curtain which then closes, shutting off the light exposure.

 

High-speed sync flash is your DSLR’s ability to use a flash at shutter speeds faster than the camera’s native sync. Most cameras have a native sync of 1/250th of a second, and anything faster than that is beyond the camera’s ability to sync the shutter with the flash.

 

Maximum sync speed can vary with camera model and shutter type, but ballpark is typically around 1/200 second, maximum shutter speed with flash (called maximum sync speed). The focal plane shutter simply is not fully open to sync flash faster.

 

Slow sync flash combines a burst of flash with a slow shutter speed. On compact cameras slow sync flash is often known as night mode and you can’t control the speed of the shutter or the strength of the flash but you can with a DSLR.

 

It’s called High-Speed Sync, also known as Focal Plane Sync. High-Speed Sync(HSS) works in a unique way. Instead of firing the flash at the start of the shot, HSS pulses the flash throughout the whole exposure, trying to simulate the effects of a continuous light.

 

Sync speed is the fastest shutter speed you can use with flash, period. You cannot use a faster shutter speed than the sync speed with flash. If you try on a camera more than about 20 years old you’ll get a partial blackout of the image, and modern cameras override you electronically when the flash is on.

 

Slow Sync is a feature available on a wide range of digital cameras that enables you to fire the flash at lower shutter speeds. You might wonder why would you want this ability. It permits you to keep shooting in a variety of low-light situations, thereby opening up new possibilities. By using slow sync flash, you can get a properly illuminated subject/foreground, yet still have the low ambient light in the foreground and background register in your frame. Many digital cameras let you set slow sync flash manually, but even on point and shoot cameras you have the ability to shoot at slow sync (typically marked as “Party” or “Night” mode on the Automatic Program selector). You probably haven’t experimented with these modes on your camera, but give it a try. Review the results and think about how you can best use this new tool in your artist’s tool box.

 

How Slow Sync Flash Works

The slow sync flash mode lets you select the synchronization of shutter speed and the power/duration of the flash. When you use slow sync, the shutter remains open much longer to allow in more light for your exposure. This means that your main subject needs to remain as still as possible, or if they move slightly their edges will be soft. The flash fires at a specific moment during the longer exposure (which you can select) and the flash duration is much shorter than the shutter speed in “standard” flash mode. Usually flash photography freezes your image, but the extended shutter speed causes the background to blur out, but is effectively illuminated — and very much sharp because of the flash. You can use smaller apertures, too, to ensure greater sharpness in the final image.

 

When to use Slow Sync Flash?

 

You’ll want to use slow sync flash in any low-light situation when you feel that the normal flash will give you a bland, staid photo. Another application is when photographing an action/sports subject and you want to capture the action with a panning technique (use rear curtain sync for this.) Due to the lower shutter speeds associated with slow sync flash, you need to stabilize the camera to avoid camera shake. You’ll likely need a tripod or monopod with slow sync flash and may want to consider using a cable release to avoid as much camera shake as possible.

 

What is Rear and Front Curtain Sync?

 

When you set your camera for slow sync flash you will most likely be presented with the two options (rear or front curtain sync). As with high sync flash this choice gives you the ability to tell the camera when you want the flash fire. This can either be when the front curtain moves at the beginning of the exposure, or when the rear curtain begins to move at the end of the exposure. Both modes will give you different final results. Rear curtain sync tends to give a faint image trail and a tack-sharp main subject, whereas front curtain sync tends light up the main subject and acquire the ambient light. It’s up to you to do some experimentation to determine the specific photographic properties for each curtain sync mode. This will give you greater proficiency in using the myriad of tools at your disposal.

 

Conclusion

Slow sync flash provides you with creative options when you’re shooting at night or indoors, and it is a great way to avoid the “cliché”, or uninspired images that you’ll most likely obtain using standard flash mode. Slow synch flash expands the boundaries of flash photography by letting you capture motion (in the form of motion blur) that would normally be missing from a traditional flash photograph. In addition, you get to manipulate an illuminated background without sacrificing depth of field choices.

Using a wide open aperture allows a lot of light to enter the camera and the exposure time now will be very short, sometimes too short. Here is what I mean. Using a flash may allow you to isolate your subject even more, but common small flashes fire for only a very brief moment, like 1/250s or maybe only a 1/20,000s.

Once you drop the exposure time on your camera, below the so-called “sync speed” however, the camera won’t expose the whole sensor for your dialed in exposure time, but a narrow slit will travel over the sensor exposing only a part of it at a time.

So if the sync speed of your camera is slower (e.g 1/160s) than the longest time your flash is on, you will find a part of your image under exposed.

In Second Image, Photo was exposed for 1/250s, which is shorter than the sync-speed time of the camera (1/160s) meaning the flash needed to fire for 1/160 of a second, not just the exposure time of 1/250s. Again the small slit traveling across the sensor exposed every part of it for just 1/250s, but its travel-time was 1/160s.


 

What are the various types of Lenses? Compare any three types.

A camera lens (also known as photographic lens or photographic objective) is an optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically.

 

There is no major difference in principle between a lens used for a still camera, a video camera, a telescope, a microscope, or other apparatus, but the detailed design and construction are different. A lens might be permanently fixed to a camera, or it might be interchangeable with lenses of different focal lengths, apertures, and other properties.

 

While in principle a simple convex lens will suffice, in practice a compound lens made up of a number of optical lens elements is required to correct (as much as possible) the many optical aberrations that arise. Some aberrations will be present in any lens system. It is the job of the lens designer to balance these and produce a design that is suitable for photographic use and possibly mass production.

 

Normal/ Standard Lenses

These are lenses are provided by the camera manufacturers along with the camera as a part of the kit. A standard lens is one with a mid-range focal length, typically around 50mm[or 18-55mm]. They have an angle of view which is roughly the same as the angle that the human eye can comfortably view, meaning that they produce images which appear “natural” to the viewer.

 

Standard camera lenses usually have a fixed focal length and wide aperture, giving them excellent performance in low light. They are popular for a wide range of photography subjects, including landscapes, portraits, and candid shots.

Telephoto Lenses

These are the lenses with focal length longer than the standard lens. Also called as Long Focus Lens. These lenses are generally used to take photographs from a distance. Especially for nature and wildlife photography where you cannot get closer to the subject physically, these long lenses help you in filling the frame with the subject from a distance. Normally, 70 – 300mm lens is recommended for such purpose though different combinations can be used based on your requirement.

 

A telephoto lens has a long focal length and provides a high level of magnification, allowing you to photograph subjects at a moderate to far distance. They tend to be bigger and heavier than other types of lens, although modern technological advances have made them more compact and easier to handle.

Telephoto lenses are popular for any type of photography where you can’t get near to the subject, including wildlife and sports events. They are also commonly used in portrait photography, where a moderate telephoto lens will provide a natural, undistorted perspective.

Wide Angle Lenses

These lenses have lower focal length than the standard lenses which helps in getting more area of view in the frame from the same distance. Typically used for taking landscape photographs, these lenses can increase the perspective distortion. So, caution is recommended.

A wide angle lens is one with a short focal length. They provide an angle of view beyond that of a standard lens, allowing them to capture more of the scene in a single shot. Extreme wide angle lenses are known as fisheye lens; these can capture around 180 degrees, making for some intriguing, almost abstract photos.

Wide angle lenses are useful for photographing landscapes, cramped interiors, and other subjects which won’t fit into a normal lens’s field of view. Fisheye lenses take this even further, and are popular for photographing action sports like skateboarding and surfing, where their inherent distortion gives photos a dynamic feel.

 

Zoom Lenses

Zoom lenses are the lenses with variable focal lengths. In these lenses the positive and negative elements of the lens are put together in such a way that by moving them you can get varied focal lengths. You can also find telephoto lens with zoom lens capabilities. A zoom lens could “zoom” from a short (wide-angle) to long (“telephoto”) focal length, making things look bigger and closer as you zoom in. Or it could zoom from an extreme wide-angle to a moderate wide-angle, never coming close to a “telephoto” focal length. Or any other range of focal lengths.

 

A 300mm lens is a telephoto but is not a zoom because 300mm is high mm (in other words, ‘long focal length’ or ‘zoomed in’) but it does not cover a range of focal lengths. (You can only use that lens at 300mm, not 299mm or 472674mm) Insead, we call these lenses prime lenses. A prime lens does not cover a range of focal lengths, just one.

 

A 10-20mm lens is not a telephoto lens but is a zoom lens. It is not zoomed in at all. It has a short focal length, low mm. It’s called wide angle. If you felt like it, you could shoot at 15mm when you feel jumpy and 16mm when you feel bumpy. You could not, however shoot at a high focal length as you could with the 300mm lens

 

Prime Lenses

As opposed to zoom lenses, prime lenses have fixed focal length. These lenses generally have lesser moving parts as compared to zoom lenses and thus reduce the problems like chromatic aberrations. Prime lenses are also referred to as the fast lenses. These lenses generally have larger apertures which allow you to photograph in lower light and create wonderful bokeh effect.

Macro Lenses

These lenses are designed to do close up photography like flowers, insects, etc. Basically the macro lenses have very high focusing movement than the normal lenses. They have a different internal construction from normal lenses which gives them very good sharpness and contrast, meaning that they produce some really eye-catching photos.

Macro lenses are useful for photographing any subject at very close range. Typical subjects include insects, animals, and plants, but they are also popular for taking extremely detailed photos of everyday objects.

Fisheye Lens

A fisheye lens is an ultra wide-angle lens–any lens with a focal length less than 15mm.  These types of lenses tend to have about a 180-degree field of vision. The effect you achieve with this lens makes it seem like you are seeing the world from inside a fishbowl–hence they name, “fisheye.”  Everything along the edges of your photo becomes extremely distorted, and your subject will seem much larger than normal. Some common uses of fisheye lenses are for photographing action sports, landscapes, and to capture unusual perspectives.  These lenses are great for getting creative–but be warned, their novelty tends to wear off pretty quickly!

Focal Length

Lens Type

Common Subjects
8mm – 24mm Ultra wide angle (fisheye) Wide panoramas and skyscrapers, artistic
24mm – 35mm Wide angle Interiors, architecture, landscapes
35mm – 85mm (50mm common) Standard General purpose
85mm – 135mm Short telephoto Portraits, candid
135mm – 300mm Medium telephoto Close sports, action
300mm+ Super telephoto Far sports, wildlife, nature, astronomy

 


Define Depth of Field. Discuss the factors that affect Depth of Field.

 

What is depth of field (DOF)

The simplest definition for depth of field is the area of your image that is in focus. More specifically, the distance between the nearest and the farthest object that are in focus. The shallowness of  the depth of field depends of the f/stop also known as aperture, the focal length of the lens, the size of the camera sensor and distances between you, the subject and the background.

 

Aperture [ f stop ]

When you look at camera lens you are going to see a maximum aperture range for that lens.

For Example f/3.5 – 5.6. The main purpose of the lens is to collect light and deliver it to the camera sensor.

The aperture of a lens is the diameter of its opening. Aperture is expressed as a f/stop. The smaller the f/stop number (or f/value), the larger the lens opening (aperture). Depth of field depends of the size of the opening of the aperture. The larger the aperture opening is the more shallow the depth of field will be and opposite vice versa.

Aperture (A.K.A F-Stop)

Aperture is one of the easiest ways to control your depth of field. It’s why photographers love lenses with a 1.2 maximum aperture. Open your aperture all the way to 1.2 and you’ll get that creamy bokeh (blur) we all love in the background. The gif animation above illustrates quite well how aperture affects depth of field, or as the definition above says, how many of the objects in the scene will appear to be in focus. For a shallow depth of field (at a wide open aperture, f/2.8), only a small plane of the image will be in focus, like the one toy in the middle there. With a wide depth of field (and a closed down aperture, f/22), almost the entire image is in focus.

Aperture is one of the most-known factors which controls the depth of field. The easiest way to understand this is, the lesser the aperture value, the shallower will be the depth of field which is ideal if you need to create blur effect in portraits and macro photography. Similarly, the higher the aperture value, the deeper would be the depth of field which can be used for landscape and cityscape photography to get the maximum area in focus.

 

 

  • The smaller the f-stop number = the bigger will be the aperture opening = the shallower the depth of field (more blur effect)
  • The higher the f-stop number = the smaller will be the aperture opening = the deeper the depth of field (less blur effect)

 

 

Changing the aperture value will also affect the shutter speed. Reducing the aperture value will increase the shutter speed and increasing the aperture value will decrease the shutter speed.

 

Subject To Camera Distance

The closer your camera is to your subject, the more shallow depth of field you will have in your image. Pull your camera far away from your subject and more items will be in focus, even when using the same aperture. 

In this image, yes the aperture is at f/2.8, which will help us get that blur in the background, but the camera is also right up close to the subject, which allows the foreground to be in focus and the background out of focus.

In contrast, this image was also shot at f/2.8, but since the camera is far from the focal point (the bride and groom) much more of the image is in focus, including the first several rows of people in the congregation.

 

Lens Focal Length

Did you know the focal length of your lens will also affect your depth of field? This is one reason portrait photographers love their 70-200mm massive lenses. They can get some amazingly shallow depth of field when shooting at 200mm. In contrast, landscape photographers shoot with wide angle lenses, not only so they can fit more in the scene, but so they can achieve sharpness in the maximum amount of the image as possible.

In this example, the image is shot with a longer focal length lens (100mm). Even though the aperture is closed down to 7.1, since the focal length is longer, the background is compressed and blurred out.

In this example, at the super wide angle of 17mm, most of the image looks pretty sharp. This is surprising since you would think you would need to have your aperture at a lower number like f/11 or f/22 in order to get an image to be this sharp. You can see how much the focal length of the lens really affects depth of field here.

 

Camera Sensor Size

Let’s think of a pocket camera. Have you ever noticed that when you shoot with such a camera you almost never get a shallow depth of field and everything is sharp in focus? That’s because the sensor of the pocket cameras is so small. But if we take a look at cameras with bigger sensors, for example full frame cameras or with a crop factor of 1.5/1.6, you will see that the depth of field is more shallow. To summarize, a bigger the sensor size allows you to achieve a shallower depth-of-field.

If the f-number is doubled, then the depth of field is also doubled. Note that “doubling” here literally means doubling (e.g. from f/4 to f/8), it does NOT mean one whole stop (e.g. from f/4 to f/5.6).

 

If the subject distance is doubled, then the depth of field is increased by four times (depth of field is proportional to the subject distance squared).

 

If the focal length is doubled, then the depth of field is decreased by four times (depth of field is inversely proportional to the focal length squared).

 

 

Explain Light meter. Compare between Incident light metering & Reflective light metering.

A light meter is a device used to measure the amount of light. In photography, a light meter is often used to determine the proper exposure for a photograph. Typically a light meter will include either digital or analog electronic circuit, which allows the photographer to determine which shutter speed and f-number should be selected for an optimum exposure, given a certain lighting situation and film speed.

 

Light meters are also used in the fields of cinematography and scenic design, in order to determine the optimum light level for a scene. They are used in the general field of architectural lighting design to verify proper installation and performance of a building lighting system, and in assessing the light levels for growing plants.

 

How the camera light meter works

When you point your camera at a scene you also need a way of measuring the incoming light so you know how much of it there is and what settings you (or your camera) need to control in order to get the shot you want. It’s just like measuring the temperature of your food with a thermometer to make sure it’s done properly.

 

Most cameras today use a process called TTL Metering, which stands for through-the-lens. It means that your camera examines the light coming in through the lens and evaluates the brightness of the scene. Then you, or your camera, can adjust the settings in order to make sure your photo is exposed how you want. You may not ever notice the light meter at work or even see that it’s there at all unless you shoot in Manual Mode. However, it’s constantly monitoring the light whether you know it’s working or not.

 

View the metering scale in Manual Mode

To see the light meter doing its thing, put your camera in Manual Mode and look for a series of dots or vertical lines at the bottom of your camera’s viewfinder.

In Manual Mode, look at the bottom of the screen in your viewfinder.
Notice the scale with zero in the middle. That is the light meter at work.

 

The number scale at the bottom of the image above is an example of a camera’s light meter, and the tiny little triangle shows whether the picture is properly exposed or not. In this case, the triangle is at 0, which means the image is neither under or overexposed, but changing the aperture, shutter speed or ISO would make the triangle move up or down the line accordingly and result in a picture that is either a little too bright or a little too dark

 

Reflective versus incident metering

 

Incident light measures the light falling on your subject and how light or dark the subject is has no effect on the exposure reading.

 

Reflected light measures the light reflecting off your subject, and the color and value (how dark of light your subject is) affects your reading, requiring evaluation and experience to accurately apply this information.

 

In terms of speed, incident is the faster way to get an accurate, ready-to-shoot exposure of a subject in the same light or shade in which you stand. Reflected readings are very useful when your subject is in shade and you are not, or vice versa – but again, the reading you take with reflected can only be “ready-to-shoot” if you are indeed pointing at something that is “middle gray” in value.

 

The first time you use an incident meter is one of those “a-ha!” moments. Once you take a reading with the lumisphere, set the camera to same and find that your exposure is right on, we bet you will wonder how you ever lived without it!

 

We will further have a detailed explanation on how it works.

 

Reflective metering

The former, (the type of metering used in DSLRs), works by measuring the amount of light that comes through the lens. But the problem with that is that unless you are pointing your camera directly at the light source, the light being measured is actually bouncing off your subject first.

 

All the colors we see in the world around us get their hues and tonal values by absorbing every color of light except for what is bounced off of them. As many of us learned in grade school, light is made up of a spectrum of colors including red, orange, yellow, green, blue, indigo, and violet. A green tree leaf absorbs every color of light except for green. A red car absorbs every color except for red, and so on.

When your camera measures incoming light, it’s looking at the amount of light being bounced off your subject, not the amount of light actually hitting your subject. This has huge implications and can dramatically affect your exposure. In the illustration above, the subject is wearing clothes that absorb most colors of light except for blue, which means there is still a great deal of light being bounced off him and sent to the camera. However if this dipshit the boy changes clothes things can change a great deal.

In the illustration above, even though the amount of light hitting the boy has not changed, the camera will read the scene much differently because he is now wearing a dark shirt and pants. The camera will think it needs more exposure to compensate for what it thinks is less light on the scene, and the overall image will be overexposed as a result.

 

Here’s a real-world example of how this works:

Nikon D7100, 200mm, f/2.8, 1/8000th of a second.

 

In the photo above, so much light was being reflected off the girl’s white shirt that the camera had a hard time metering the scene properly. Much of the sunlight was bouncing off the shirt and coming directly back to my camera, so it responded by using a very fast shutter speed and low ISO value in an effort to make sure the shirt was properly exposed. Unfortunately, the rest of the scene was underexposed as a result.

Nikon D7100, 200mm, f/2.8, 1/1500th.

 

This was a few seconds later in the exact same spot, the only difference is of a darker or brown shirt. With much of the light from the sun being absorbed by the dark color of her outfit, the camera created a much brighter exposure by using a slower shutter speed. Not as much light was being captured by the TTL metering system so the camera thought more light was required for a good exposure.

 

Incident metering

This phenomenon can be particularly troublesome if you are shooting a wedding; grooms often wear dark tuxedos whereas brides will usually be dressed in dazzling whites, which can really throw off your camera’s TTL metering system[Through-the-lens metering].

The solution is to use an external handheld light meter, such as the Sekonic L-308S-U, which actually measures the amount of light falling on the subject.

 

In the image, you can see that the meter shows you need an aperture value of f/16, shutter speed of 1/125th of a second, and ISO 100 in order to get a properly exposed scene. These numbers will likely be different from what the camera’s TTL system measures because some light will invariably be absorbed by the subject, which is why an external system like this can be so useful.

 

Here’s how the diagram from earlier would look if the setup involved an external handheld incident light meter.

You will often see wedding photographers[not self proclaimed please] using a light meter such as this in order to get a more accurate reading of how much light is hitting the wedding party during formal photos. This is especially true if they’re using a system of flashes or external speedlights because they need to know how much extra light the scene will require or tolerate.

 

When shooting a wedding it is quite common for the bride to wear a white dress, which reflects a great deal of light, and the groom to wear a dark tuxedo which absorbs almost all light. This can wreak havoc with a TTL metering system, and an external light meter is a great way to address the problem.

 

Conclusion

The overall goal here is to understand how the light meter in your camera functions. This, in turn, will help you know how you will need to alter the exposure settings to get the shot you want.

 

Knowing the difference between the various metering modes and types, and understanding how light is measured as it hits your camera can help you get the shots you want. None of these methods are any better or worse than the other, but each one has its own strengths and weaknesses. The more you know about how all of this works the better equipped you will be to get precisely the photographs you want.


Explain exposure metering in camera. Describe the need of various metering modes.

 

Exposure is a complex beast. Mastering it is of the utmost importance. Exposure and composition are the two most critical components towards making a great image. Exposure is based on three components:

 

  1. The ISO or sensitivity to light
  2. Aperture or the size of the opening that will let in light, and
  3. Shutter Speed which defines the duration the light will have to pass through the aperture

 

Whether you shoot in Manual, Aperture Priority or Shutter Priority; there is no difference in how the meter evaluates the scene.

 

Measuring the light, or brightness of the scene you are trying to capture, is a critical component in determining the perfect exposure. To establish this you need a meter that can read the levels of brightness.

 

Exposure is measured using light meters.  There are two types: one measures the light falling on the subject or scene, called an incident light meter; the other measures the light reflected off the scene or your subject, and is called a reflected light meter. All meters that are built into digital cameras are reflected light meters, and we will be addressing that type in this article. The more you understand these meters and how they work, the better you will be at understanding and interpreting what they are telling you. Keep in mind that incident light meters are far more accurate than reflected light meters.

 

How does your camera determine exposure?

Reflected light meters attempt to read the amount of light in the scene you are trying to capture. Unfortunately, those readings are guesses. You may have had the misfortune of photographing a very dark or black subject and have it come out looking over exposed, or a snow scene where the snow looks grey or under exposed. The reason for this behavior is that the camera’s light meter believes that most scenes should average to a mid-grey, also referred to as 18% grey. This middle grey is a mid-point between the darkest shadows and the brightest highlight. Since the camera meter has no idea about white or black, you need to help it using some form of exposure compensation based on the tonality of your subject or scene.

 

Metering Modes

To help with exposure, and determining how much to compensate, cameras have various metering modes. Typically, the three basic modes are Matrix (also called Evaluative), Center-weighted and Spot metering. Each of these is applicable in particular situations, but do not rely on just one of these modes to do it all for you.

 

 

1. Evaluative Metering


The camera looks at the light in the entire scene and averages it, (Nikon puts a bigger emphasis on the area where your lens is focused as well). Nikon calls this Matrix Metering, Canon calls it Evaluative.

 

Matrix metering works well for scenes that are evenly lit.  It can be used as a go-to method for grab shots. Even though the camera meter may fail you, these meters are highly sophisticated, computer controlled devices and can be relied upon for general photography. You can leave your camera on this mode and use it as a means of exposure education.

 

In this metering mode, the meter divides the scene up into a grid and analyzes each segment for highlight and shadow (bright and dark) information. Once that data is collected, it calculates the average value and bases the exposure on that average. Keep in mind that all cameras do not have the same number of areas within the frame. Also, they don’t all calculate the average value for exposure the same way.

Manufacturers use complex formulas to arrive at exposure values.  Therefore, it is important that you understand how your camera behaves in various situations and learn when to trust it, and when not to trust it.

 

Many of the newer DSLR’s not only average the grid, but place additional emphasis on the focusing points that are in use during that particular image capture.

 

2. Center-Weighted Metering

 

Looks at the light of the entire scene and averages it, but with emphasis on the center of the frame. Nikon and Canon both call this Center-Weighted Average Metering.

Use this for any scene where you want the primary subject to be correctly exposed while the rest of the image can be generally ignored for proper exposure. This is ideal for people and pet portrait photography, Still life and some product photography.

 

Center-Weighted is much more consistent and predictable compared to matrix metering. Use it wisely to control where the camera will be measuring the scene and those areas where the lighting does not play a key role in your composition.

 

Use this mode for outdoor portraits, high contrast scenes, product and food photography to name a few.

This method of metering lays the most importance on the central portion of the frame, which can be as much as 75% or more, while little or no importance is given to the corners of the frame. Many pro DSLR’s will allow you to adjust the diameter of the center weight area.

 

This mode of metering is preferred by many photographers and has a reasonable level of accuracy.

 

Also keep in mind that most subjects tend to be centrally placed when framing. You then obtain the exposure and recompose before capturing the image.

 

3. Spot Metering

Measures the light only in a small area around the central autofocus point (about 1.5-3% of the frame). Nikon and Canon both call this Spot Metering. Spot metering gives the maximum accuracy and exposure control.

This is ideal for back-lit subjects, close-up and macro photography. It can be used to read the brightest and darkest zones for landscapes.

 

You could not do lunar photography without this mode. Remember to use this mode any time it is important to correctly expose for a subject that does not fill the frame.

 

Spot metering mode works exceptionally well in situations where your primary subject is much lighter or much darker than its surroundings.

This mode measures the light from a very small part of the scene only.  The area measured is typically the center of the image, using approximately a 3 to 7 degree range of measurement.  It is usually less than 5% of the area of the frame.

 

With most of the mid to upper end DSLR’s, you can arrange the placement of the spot within the frame so as to identify where you want the reading captured (usually it follows where you focus).

 

This is a very accurate metering mode. It will provide precise readings from small areas of your scene and is most effective in high contrast situations.

 

Exposure compensation

In a number of situations, you will need exposure compensation to get the right exposure, irrespective of the metering mode you select. Scenics with a lot of snow cover will be under exposed and will require an increment of +1 or more stops of exposure to make the snow look white.

 

Conversely, a black furry bear or a person wearing very dark clothing will be overexposed and will require negative exposure compensation of -1 or more stops.

 

Other camera manufacturers have different names for these modes, but suffice it to say the way in which your camera measures incoming light can have a huge impact on whether your photo is properly exposed. As an example, here are three shots that were taken with different metering modes.

Image #1, taken with Matrix (Nikon) or Evaluative (Canon) Metering.

Image #2, taken with Center-Weighted Metering.

Image #3, taken with Spot Metering.


Describe parameters of light.

If there is one essential ingredient for photography, it is light. It really wouldn’t matter how much money you put into your lenses and cameras if they were unable to gather, focus, direct, and record light; your gear would be nothing more than a collection of overpriced paper weights. But image creation doesn’t fall entirely to the camera. The photographer needs to know how to use light. In order to harness the power, dynamism, and idiosyncratic nature of light, it is absolutely necessary for a photographer to establish a real relationship with light. As is true in human relationships, understanding is a key component. Any photographer who wishes to reach their full creative potential should, likewise, make it a point to understand the vital characteristics of light.

 

1. Intensity

The intensity of light may also be referred to as quantity of light. This is just a way of speaking about the amount or strength of light present. As a practical example, think of how your eyes react when you walk into a dimly lit room after spending some time in a brightly lit room; for a moment, you can’t really see much of anything. Everything is underexposed.

The strength of light is called is called intensity. The intensity indicates how much light is there in the scene. We know that right amount is light required by the eye to see properly. So is the case with camera. Human retina is designed to handle a narrow range of brightness. Any excess amount is unbearable and the eyelids tend to close to protect retina from damaging.

 

Similarly, the image sensor or the film is designed to work efficiently in a narrow range of brightness. It cannot produce a proper image in excess light neither in low light. The allowance of exact amount of light to enter the camera needs a complicated mechanism that can work with utmost simplicity for a working photographer. This system of controlling the intensity of light is called Exposure System.

 

2. Quality

The word quality makes us think of better craftsmanship, better finishing better performance and so on. How is quality related to light? What are the means to understand the quality of light? How can we judge good and bad light?

[SHITTTT I NEVER THOGUHT ABOUT THSIE QKUESTION]

 

This is subjective. The light good for one situation may be worse for the other. The light which is suitable for an identity card photography is simply flat for a portrait. The light for a landscape is simple unsuitable for fashion picture. When you have to bring out the texture of a denim cloth you can use a different kind of light than the type of light to subdue wrinkles on a middle aged woman desirous to look young

 

In simple terms, quality of light is softness or hardness of light, and it can be judged by the kind of shadows it creates. As we know that light is not visible but it makes the thing visible. The shadows are definitely visible and help us judge the quality of light. A soft light will create soft shadows and a hard light will cause harsh shadows.

 

The quality of light is not something we can measure. It is, instead, something we describe based upon visual perception; light is either soft or hard (or some similar descriptive variation).

 

Soft light is non-directional and typically comes from a diffused source. When you’re using flash and you aim the flash into a white umbrella, for example, you are diffusing the light and softening it. Soft light helps creates smooth, gradual transitions from light to dark without causing strong shadows to appear.

 

Hard light is harsh, directional, and casts strong shadows and bright highlights. If you’ve ever attempted to take a portrait of someone under the midday sun, you likely noticed your subject’s facial features — particularly the eyes, nose, and neck — cast or were beset by harsh shadows. This is a typical trait of hard light.

 

Portrait photographers overwhelmingly prefer soft light because it is perceived as more flattering. As alluded to above, photographers use a wide variety of devices known as modifiers in an effort to soften the otherwise harsh light of their strobes and flashes. However, natural light can be diffused also; shooting on a cloudy day or using the sunlight trickling in through a window can create beautiful soft light.

 

3. Color Temperature

Color temperature is all about mood. A photograph may have a color cast or tint of sorts that strikes the viewer as being “cool” or “warm.” This, of course, has nothing to do with the weather at the time the shot was taken. Contrary to what we perceive with our eyes, light isn’t typically crystal clear — it actually has a color to it and that color can vary under certain conditions.

 

A photograph taken in deep shade, for instance, may have somewhat of a blueish hue to it; this is a shot we would refer to as being cool. Conversely, the golden light of sunset would translate into a warm shot.

 

Color temperatures are measured on the Kelvin scale and range from roughly 1000K on the warm, red end to 10,000K on the cool, blue end of the scale. As a point of reference, daylight and electronic flash fall into the 5000 to 5500°K range; tungsten/incandescent bulbs are rated at about 2500°K to 2800°K.

 

Color temperature has a profound impact on photography. Depending on what type of lighting you are using on your subject, it has the potential to cause some undesirable color casting in your shots. To work around this and ensure that your photos are accurate representations of the scenes you are shooting, you will have to adjust your camera’s white balance to even things out.

However, this is yet another area where there is a lot of subjectivity. A cool scene can be warmed, a warm scene can be cooled down, a feat made extraordinarily easy with digital photography. Plus, if you shoot raw you can fix color temperature in Lightroom, Photoshop, GIMP, or just about any other image editor. A basic understanding of color temperature and white balance will give you greater creative control over your photography.

 

4. Direction

In addition to exercising control over the quantity, quality, and color of the lighting being used, a portrait photographer also has some control over the “shape” of their subject’s face. How? By dictating the direction from which the light is coming.

 

This is rather easy in a studio setting. All you need to do is move your key light (main light) into a position that creates the look you want; the way the light reflects in the subject’s eyes, the way it wraps around the face, the direction and strength of the nose shadow. If a multi-light setup (hair, rim, and fill lights) is being used, the position of those other lights can also be arranged to fine tune everything and further affect the shape of the face.

 

Being so precise is much trickier when working outdoors with the sun as your main light source. In this case, since the sun can’t be moved, you will have to move your subject around until you get the desired look.

 

Why does the direction of light matter so much? Because it influences how the portrait is perceived by the viewer. For example, “butterfly” lighting is a lighting technique that creates a symmetrical butterfly-shaped shadow under the subject’s nose and emphasizes prominent cheekbones and good skin. In order to accomplish this glamorous look, it is absolutely necessary to make sure the lighting hits your subject’s face in a very specific way. The direction of light can make or break a shot.


What is Motion Blur? Explain various ways to get creative motion blur

Photographs, by definition, capture and immortalize a small slice of life. There is little for the viewer to infer what happens before or after that moment. However, there are images that need to communicate motion. For example, you may want to capture a dog running, a train barreling down the tracks, or trees that are blowing in the wind. Each of these scenes can come alive within your photographs if you learn how to convey motion properly.

 

Motion blur is the blur that happens to an image when the shutter stays open long enough that it captures movement within a scene.   As something in the scene moves in relation to the camera sensor (or film), the light hitting the sensor changes, the sensor records all the light hitting the receptors while the shutter is open.  So if something moves while the shutter is open then it shows as a blur in the direction of the movement.

 

The amount of blur depends on how fast the subject is moving in relation to the camera and how long the shutter is open.  The longer the shutter is open the more it can capture small movements. For example, if the shutter is open 1 minute it can capture the very slow movement of the stars in the night sky.

 

Slowing the shutter speed

While there are many ways to create a motion blur effect, the best way to start is by slowing down your shutter speed. The reason for movement blur is simply that the amount of time that the shutter of a camera is open is long enough to allow your camera’s image sensor to ‘see’ the movement of your subject.

 

If your shutter speed is fast (eg 1/4000th of a second) it’s not going to see much movement (unless the the subject is moving mighty fast) while if you select a longer shutter speed (eg 5 seconds) you don’t need your subject to move very much at all before you start to see blur.

 

When the shutter is open longer, the subject has more time to move across the frame and establish some kind of blur. Think of it this way. How far does your hand move in front of your eyes in 1/500th of a second? Okay, that’s a tough one to answer. But for contrast, ask yourself the following: How far does your hand move in front of your eyes in 3 seconds? Obviously, it’s much further. The same rule applies for cameras.

 

Consider your exposure

Here is another factor to consider. Every scene has different light levels. In the middle of the day with the sun shining at its peak, a lot of light will be entering your camera. The problem with slower shutter speeds is that they let more light in every time you take a picture. When it is bright and sunny outside, this can quickly lead to exceedingly bright pictures with washed out colors. In other words, it leads to overexposure. To compensate for this, you either have to close the aperture more (use a higher f-stop number), adjust ISO to a lower number, or place a light blocking filter in front of your lens.

 

Try shutter priority mode

One of the most important settings in photographing an image which emphasizes movement is the shutter speed (as outlined above). Even small changes in shutter speed will have a big impact upon your shot – so you want to shoot in a mode that gives you full control over it.

 

This means either switching your camera into full Manual Mode or Shutter Priority Mode. Shutter Priority Mode is a mode that allows you to set your shutter speed and where the camera chooses other settings (like Aperture) to ensure the shot is well exposed. It’s a very handy mode to play with as it ensures you get the movement effect that you’re after but also generally well exposed shots.

 

In shutter priority mode, you need only tell the camera the shutter speed you are looking for, and it will automatically pick an aperture and ISO for the scene you are photographing. While shutter priority mode works in a wide variety of situations, it isn’t a fix-all for every photographic scene. Your camera may have a great light metering system to help it pick the right aperture and ISO settings, or it might not. Always double check your photos after you take them to make sure they are being exposed correctly.

 

Shutter Speed

So how slow should your shutter speed be? It all depends on the effect you are looking for. The longer you leave the shutter open, the more motion blur you will have. Images will begin to blur slightly at any shutter speed below 1/500th of a second. When you get near the 1/15th of a second range, blur will become very noticeable.

 

Panning

One easy way to create a motion blur effect is to follow your subject with your camera while you are taking the photo. This is known as panning, and it creates a really cool effect. If you have picked your shutter speed correctly, and you can manage to follow your subject fast enough, your subject will appear still in the photo while everything else around it is blurred in the direction of the subject’s motion.

 

Tripod/Stationary Camera

All other motion blur photographs require the use of a tripod. There is simply no getting around this. When you use a slower shutter speed, everything in the frame can become blurred unless you are holding the camera perfectly still. These are known as camera shake issues. The tripod keeps the camera still while the subject moves throughout the frame, blurring only the subject while keeping the background crisp and clean. In the image to the right, the water is blurred but the background is sharp. Without a tripod, the longer shutter speed needed to make the water blur would also have caused the background to blur because of a small amount of camera shake.


What various exposure modes are offered in a camera?

 

Mode

Shutter Speed

Aperture

P (programmed auto) Selected by camera Selected by camera
S (shutter-priority auto) Selected by photographer Selected by camera
A (aperture-priority auto) Selected by camera Selected by photographer
M (manual) Selected by photographer Selected by photographer

 

The 4 basic exposure modes that are found on most DSLR, Mirrorless, and Advanced Compact Cameras. These exposure modes are sometimes referred to as the PASM modes and can generally be located on your camera’s mode dial, although some compact cameras may put these options in the menu system. The mode dial and camera menu system may also include several automatic scene modes like Landscape, Night, Portrait, Macro, Sport, Sunset, and more.

 

Manual-enabled modes give the photographer control over the various parameters of an exposure. There are three exposure parameters – aperture, time (shutter speed), and sensitivity (ISO), and in different modes these are each set automatically or manually; this gives 23 = 8 possible modes. For a given exposure, this is an underdetermined system, as there are three inputs but only one output. Accordingly, there are many combinations that result in the same exposure – for example, decreasing the aperture by one stop but increasing the exposure time or sensitivity to compensate, and there are various possible algorithms to automatically choose between these.

 

Most often, ISO is considered separately, being either set manually or set to Auto ISO, and then only aperture and shutter speed need be determined – either determines the other.

PASM is an acronym for Program, Aperture Priority (Referred to as Av on Canon), Shutter Priority (Referred to as Tv on Canon), and Manual. These exposure modes, especially the first three, are a great way to explore how exposure variables interact.

 

 

In addition to these exposure modes, your camera will likely have a fully automatic mode that lets the camera make all of the exposure decisions for you. Shooting in automatic mode will generally result in reasonably good photos, but you will find that using auto mode doesn’t always allow you to capture the scene the way you envisioned. Maybe you’re not quite ready to start adjusting all of the exposure variables manually yet, but still want to start experimenting with some manual settings. Take your time and get to know your camera and its exposure modes that offer some manual control, without putting you in charge of figuring out all of the settings.

 

Program Mode selects the optimum shutter speed and aperture. However, you can change either of these settings yourself and the camera will adjust the other one to keep the exposure correct. If you want a shallower depth of field, you simply select a lower f-stop setting and your camera will increase the shutter speed to compensate. If you want motion blur in your image, you can reduce the shutter speed and your camera will adjust to a smaller aperture (higher f-stop). Using Program Mode is an excellent way to familiarize yourself with the exposure variables.

 

Aperture Priority (Av on Canon) lets you choose your aperture setting which helps to determine your depth of field. Based on your aperture setting, the camera will calculate what your shutter speed should be. If you’re shooting in lower light, this can sometimes result in photos that are blurry if you’ve selected a narrow aperture. Aperture Priority Mode is a good choice if you’ve got lots of light to work with, are photographing a subject that isn’t moving quickly, and want to achieve a very specific depth of field in your photo.

 

Shutter Priority (Tv on Canon) lets you choose a fast or slow shutter speed and lets the camera decide on the aperture setting needed to get a properly exposed photo. Because the camera gets to choose the aperture setting though, this means that the depth of field in your shots will not be consistent. If you’re shooting fast action like a track and field match or a fighter jet flying past and need to be sure that your shutter speed remains quick enough to capture these moving subjects Shutter Priority Mode can be the right choice. Keep in mind that if the lighting conditions keep changing, you may end up with backgrounds that are different in each shot since the depth of field will keep changing.

 

Manual Mode puts you totally in charge of figuring out the right exposure for each scene. In Manual Mode, you’ll need to determine what the right shutter speed, aperture, and ISO is. This is a lot to figure out for most new photographers, but once you’ve got a solid understanding of how exposure works, Manual Mode offers the greatest degree of control over your photography. If you’re still figuring out your camera, there’s no need to rush into using Manual Mode — your photos will probably be better if you stick to the other exposure modes while you learn more about all the exposure variables. Before long, you’ll be able to make the calculations in your head and can start reading a scene even better than your camera can.


Discuss the applications of slow shutter speed

 

Shutter speed exists because of something known as your camera shutter – which, simply put, is a curtain in front of the camera sensor that stays closed until the camera fires. When the camera fires, the shutter opens and fully exposes the camera sensor to the light that has passed through your lens. After the sensor is done collecting the light, the shutter closes immediately, stopping the light from hitting the sensor. The button that fires the camera is also called “shutter” or “shutter button,” because it triggers the shutter to open and close.

 

Shutter speed is the length of time your camera shutter is open, exposing light onto the camera sensor. Essentially, it’s how long your camera spends taking a photo. This has a few important effects in how your images will appear.

 

When you use a long shutter speed, you end up exposing your sensor for a significant period of time. The first big effect of shutter speed is motion blur. If your shutter speed is long, moving subjects in your photo will appear blurred along the direction of motion. This effect is used quite often in advertisements of cars and motorbikes, where a sense of speed and motion is communicated to the viewer by intentionally blurring the moving wheels.

 

Shutter speed is a critical component of the exposure triangle, along with aperture and ISO. If you want to get the best quality photos you will need to understand exposure and how each element of the triangle impacts the others. Shutter speed can also be used in landscape and nature photography to create some interesting and powerful effects.

 

Panning

Another way to use shutter speed creatively in times of action is to pan the subject. Panning is where you move the camera during the exposure to follow the subject. Done properly (or when you get lucky) the subject is relatively sharp, while the background is blurred and conveys a sense of motion.

1/15th at f/7.1, ISO 50

 

Accomplishing this is usually best at slower shutter speeds between 1/8 and 1/30 of a second. Being able to slow down the shutter speed is typically welcome news, as it will mean you do not have to crank up your ISO, or make other offsetting moves. Getting a good result will frequently require at least a few attempts, while you gauge the speed, and other settings.

 

If possible, get your exposure set up before you attempt to pan. That way you are only thinking about the panning during the shot, as opposed to worrying about all your other settings.

 

Creating a Sense of Motion

Still another creative use of shutter speed is slowing it down to create a sense of motion. This is accomplished when the subject is moving slightly through the frame during the exposure. This idea is for the subject to be identifiable, but slightly blurred.

1/4 second at f/16, ISO 50

Shutter speeds for this type of shot are between 1/4 and 1/10th of a second. That is virtually always too slow for you to hand-hold your camera, so you will probably need to break out the tripod for this type of shot.

Starry Sky

Although there is no movement in this type of image, we still require a slow shutter speed in order for the camera’s sensor to capture the detail that is usually hidden in the night sky. Because it is so dark, in order to capture stars like this we not only need to have a slow shutter speed but we also need to increase the camera’s sensitivity to light (by increasing the ISO). We can also assist the camera in this process by ensuring that our aperture is wide open (eg. f 2.8) in order to allow as much light as possible through the lens and onto the sensor. This combination of increased sensitivity to light, maximum aperture, and a slow shutter speed gives you a good base from which to start photographing the night sky.

The Quiver trees in this image were painted in using a torch and this too takes a bit of practice in order to get a correct and even exposure. This particular tip is bound to keep you busy on your next trip!

 

Light Painting

As the name suggests, you paint with light! Any light source can be used for light painting, flashlight, for example. You could even use your mobile phone. Choose a dark room so that the ‘painter’ does not appear in the painting. You could create different shapes, or write something, it’s up to you. The exposure duration depends on how much time you need to draw the shape/characters.

Long Exposures

The final creative use of shutter speed we will cover here is a long exposure. This is where you hold the shutter open for a long time and allow certain parts of your picture to move through the frame. You will always need a tripod for this technique.

20 seconds at f/8, ISO 400

Long exposure shutter speeds are between 10 and 30 seconds. Most cameras offer you the ability to go even longer by using Bulb mode, where the shutter will stay open as long as you hold the shutter button down. A remote shutter release, which is always a good idea when you are shooting from a tripod, is almost a necessity for this type of shot.

 

Long exposure is a great technique whenever there is moving water involved, such as coastal scenes, rivers, and waterfalls. It is also great for streaking lights in night photography.

 

Whereas most of the time, your challenge with shutter speed is to get enough light into the camera; in this context getting the shutter speed you want usually involves the opposite problem. The challenge is to limit the amount of light entering the camera so that you can leave the shutter open a long time without overexposing the image. To do that, first close down the aperture to its smallest setting and use the lowest ISO setting on your camera.

 

The lowest ISO setting is usually 100, but some cameras contain an expandable ISO range that will allow you reduce the ISO further, so be sure to check your camera’s menu for that.

But if those moves don’t restrict the light enough, you will need to use a neutral density filter. These are filters that restrict the amount of light coming into your camera. They come in different strengths, with typical values between two and 10 stops of light. Get one of these (or a few different strengths) and keep it in your bag if you think you will have any long exposures in your future.

15 seconds at f/8, ISO 500

Conclusion

Once you have mastered the basics of shutter speed, it is a great tool for adding creativity to your photography. It is perhaps the most effective way to make our photos more interesting.


What is exposure? What are the factors to keep in mind while deriving exposure?

 

In photography, ‘exposure’ means the amount of light that falls onto the sensor of your digital camera. In modern cameras the exposure is usually set to automatic by default and, most of the time, it can be left there and will produce beautiful pictures. There are times though, when the camera lets us down or we want to produce a particular effect and it would be nice to understand what is going on ‘under the hood’.

 

A photograph’s exposure determines how light or dark an image will appear when it’s been captured by your camera. Believe it or not, this is determined by just three camera settings: aperture, ISO and shutter speed (the “exposure triangle”). Mastering their use is an essential part of developing an intuition for photography.

 

In photography, the exposure settings of aperture, shutter speed and ISO speed are analogous to the width, time and quantity discussed above. Furthermore, just as the rate of rainfall was beyond your control above, so too is natural light for a photographer.

 

There are four major factors which determine how a camera will capture an image with good exposure. These factors are named here as light, aperture, sensitivity, and time. You can remember these four terms together with the acronym LAST.

 

  • Light (illumination),
  • Aperture (f/stop),
  • Sensitivity (iso rating),
  • Time (shutter speed)

 

With a camera, the photographer can attempt to capture an image at any time. However, the optimal photograph is made only if all four of these factors are properly balanced. A change in any of these four factors would require an adjustment to the other factors to compensate, bringing all of the factors back into harmony. Without the proper combination, the resulting image will certainly suffer.

 

These four aspects can be calculated very simply, and the proper ratios can be achieved with the appropriate numerical values of each of these four components. If all of photography were so simple, everyone would be Ansel Adams. Each of the four factors introduces its own side effect, and it’s the artistic understanding of this complex interplay which can distinguish a good photograph from a poor one.

 

For the purposes of this discussion, we will define an “ideal” image as having the widest true dynamic range with a pleasing distribution of middle shades between the lightest and darkest recorded shades. Without a good dynamic range, many important details in an image are lost and cannot be recovered with darkroom or digital post-processing.

Light controls Balance

Light (L) refers to the actual illumination from the scene which enters the camera. Our brains are very good for adapting to different lighting conditions, so it may not be intuitive to realize the importance of illumination. A camera must adapt to the incoming light in much the same way, whether through manual adjustments or automatic electronics. The available light is quite different between night-time, indoors, cloudy and sunny conditions. In addition, the illumination which enters the camera is also affected by light-colored or dark-colored subject matter.

 

On a camera, the trick to recording an image with the best exposure will be to find an appropriate combination of aperture, sensitivity and time to match the available light. Sometimes a photographer can increase the amount of light indirectly by using a flash bulb, or opening a window, or by waiting for more sunlight to be available. A filter can be placed in front of the lens, like sunglasses, to limit the amount of light.

 

With each new light source added, the overall makeup of that light is changed. Shadows are made deeper or shadows are filled in. The golden glow of your tungsten light bulb will cast across the subject. Sunny blue skies will alter the hue of your image. Use your camera’s flashbulbs and the strong mostly-white light will compete with the other illumination. The balance of all these sources will determine the color balance of your subject.

 

Films are formulated to counteract the color balance of each type of light, such as tungsten and sunlight. Digital cameras often try to determine the “white balance” automatically, to ensure that white objects look white, not too blue from the sky or too warm from the desklamp, but you can often adjust the white balance yourself.

 

Artistically, you may also use this imbalance to your advantage. You can make shadowing work to your advantage. You can add a filter to your lens to color the light. You can use a different white balance setting on your digicam. You can enhance contrast by spreading out the lights and subject differently.

 

Aperture controls DepthApe

 

As discussed, the simplest camera is called the camera obscura, which is also known as the pinhole camera. One of the drawbacks to the pinhole camera is that of convenience. A tiny pinhole can take a very long time to let enough light through, to properly expose a piece of chemical film or an electronic circuit. The very first camera obscura took a whole day to expose. The

sun’s overhead movement through all those hours made the shadows kinda silly-looking and indistinct, and nobody would pose for that long.

 

If you widen the pinhole, more light shines through. A bigger aperture directly equates to less exposure time. If you double the area of the aperture, then twice the light can come through at once.

 

The size of the film doesn’t matter, but the depth of the camera’s body does matter, in measuring the effect of the incoming light.

 

 

 

Once the aperture (A) is bigger than a pinhole, though, you’ll need a lens. A lens redirects all the light that passes through the hole, so that it comes back towards a coherent image on the film. This page won’t go into more details about the lens effect, however.

 

Sensitivity controls Grain

 

Film emulsion is made up of tiny crystals that are sensitive to light. Digital sensors are organized into tiny receptors that are also sensitive to light. When you take a picture, these crystals or receptors each react and record a single tiny piece of the whole image.

 

Film emulsions can be designed to be very sensitive to dim lights, or mostly unaffected by all but the strongest lights.

 

Likewise, digital sensors can be amplified, much like a radio volume knob, to increase weaker light signals. However, the penalty of using more sensitive films or amplifying the receptor signals is that it can create an image which has many small variations. These variations in light or color in a photograph are called grain (film crystals) or noise (electronic receptors). It’s very much like the static you hear on the radio, when the signal is not strong enough to be received accurately.

 

Time controls Action

 

As we’ve seen, we can adjust any one of the four factors to counteract any of the others. The shutter time is no different; if you have too much light, you can use a faster shutter speed to maintain your exposure; conversely, a slow shutter can brighten your image beyond what the human eye can perceive.

Shutter time is a very important factor because it means something to the observer, not just to the photographer. If any part of the scene is in motion, then the shutter time you choose is crucial to convey the action to your audience. In fact, in many circumstances, you may want to choose your shutter time first, and then adjust all of the other factors to suit your chosen shutter time.

 

 

Making Choices

We now see that exposure is based on four factors: light, aperture, sensitivity, and time. If you halve any of these, you must double another one to maintain an equivalent exposure.

 

Also, besides this simple double/halve behavior, each of the four factors controls some secondary effect. Light controls balance, aperture controls depth, sensitivity controls grain, and time controls action.

 

Selecting the appropriate combination of light, aperture, sensitivity and time usually comes down to a choice of which secondary effect is most important.

  • If low grain is most important, pick a low sensitivity first;
  • If stopping the action is most important, set a short shutter time;
  • If isolating subject from background, open up the aperture; and
  • If the shadows and color are critical, control the incoming light.

As the photographer, the priorities are yours; the camera is a tool.


Compare between human eye & camera.

I am searching for Shorter Answer. Please help. I really feel it can come in exam.

To better understand the answer to this question, let’s first have a quick comparison of various similarities and differences found in the working of the human eye and a photo camera.

Similarities

Image focusing: Human and camera lenses both focus an inverted image onto light-sensitive surface. In the case of a camera, it’s focused onto film or a sensor chip. In your eyes, the light-sensitive surface is the retina on the inside of your eyeball.

 

Light adjustment: Both the eye and a camera can adjust quantity of light entering. On a camera, it’s done with the aperture control built into your lens, whilst in your eye, it’s done by having a larger or smaller iris.

 

Camera vs Eyes: Differences

 

Absolute versus subjective measuring of light: Simply speaking, the human eye is a subjective device. This means that your eyes work in harmony with your brain to create the images you perceive

Your eyes are adjusting the focus (by bending the light through the lens in your eyeballs) and translating photons (light) into an electrical impulse your brain can process. From there onwards, it’s all about your brain: It is continuously readjusting its colour balance according to the lighting context. In other words, our eyes know what must be seen as red or white or black etc.

 

A camera, on the other hand, is an absolute measurement device — It is measuring the light that hits a series of sensor, but the sensor is ‘dumb’, and the signals recorded need to be adjusted to suit the color temperature of the light illuminating the scene, for example

Lens focus: In camera, the lens moves closer/further from the film to focus. In your eyes, the lens changes shape to focus: The muscles in your eyes change the actual shape of the lens inside your eyes.

 

Sensitivity to light: A film in a camera is uniformly sensitive to light. The human retina is not. Therefore, with respect to quality of image and capturing power, our eyes have a greater sensitivity in dark locations than a typical camera.

 

There are lighting situations that a current digital cameras cannot capture easily: The photos will come out blurry, or in a barrage of digital noise. As an example, when observing a fluorescence image of cells under a microscope, the image you can see with your eyes would be nigh-on impossible to capture for an ordinary camera. This is mainly because of the fact that the amount of light entering the camera (and your eyes) is so low.

 

Your eye as a camera

  1. Your Cornea behaves much like the front lens element of a lens. Together with the lens, which is behind the iris, they are the eye’s focusing elements. The cornea takes widely diverging rays of light and bends them through the pupil, the round opening in the central portion of the coloured iris.
  2. Your Iris and Pupil act like the aperture of a camera. The iris is a muscle which, when contracted, covers all but a small central portion of the lens, allows adjustable control of the quantity of light entering the eye so that the eye can work well in a wide range of viewing conditions, from dim to very bright light.
  3. Finally, your Retina is the sensory layer that lines the very back of our eyes. It acts very much like the imaging sensor chip in a digital camera. The retina has numerous photoreceptor nerve cells that help change the light rays into electrical impulses and send them through the optic nerve to the brain where an image (of what we see) is finally received and perceived.

    Because of this reception and perception function, retina is, perhaps, the most important component of our eyes. As with the camera, if the “film” is bad in the eye (i.e. the retina), no matter how good rest of the eye is, we will not get a good quality image or picture.

 

The real issue with the human eye is that, unlike film and camera sensors, our eyes do not have any definite ISO levels. However, our eyes do have a great ability to naturally adjust to ambient light levels even under the most severe lighting conditions.

 

However, the human eye has a mighty trick up its sleeve: it can modify its own light sensitivity. After about 15 seconds in lower light, our bodies increase the level of rhodopsin in our retina. Over the next half hour in low light, our eyes get more an more sensitive. In fact, studies have shown that our eyes are around 600 times more sensitive at night than during the day.

 

It should also be noted that the human eye is like the greatest, quickest automatic camera in existence. Every time we change where we’re looking, our eye (and retina) is changing everything else to compensate — focus, iris, dynamic range are all constantly adjusting to ensure that our eyesight is as good it can be.

 

In addition to straight-up light sensitivity (which we’ll get back to in just a minute), the dynamic range of the human eye is absolutely astonishing: A human can see objects in starlight or in the brightest of sunlight. The difference between the two extremes is absolutely astonishing — In sunlight, objects receive 1,000,000,000 times more light than on a moonless night — and yet, we are able to see under both circumstances

 

The human eye is extremely good at resolving images in bright light, and it becomes meaningless to speak of ‘noise’ — not because our eyes aren’t misfiring every now and again, but because our brain simply filters out any problems our eyes encounter (Just think about how your brain is constantly filtering out the two blind spots you have — one in each eye — even if you are closing one eye and looking with the other. If you have never experienced your blind spot — give it a shot, it’s rather astonishing).

 


How do shutter speed & aperture correlate?

 

Understanding the relationship between aperture and shutter speed will help you take full advantage of your DSLR, allowing you to have more fun capturing photos. The aperture is the size of the hole in the diaphragm of the lens. It is possible to view this device when you look right square into the lens of the camera. The aperture diameter (size of the hole) is denoted by a sequence of f-numbers. The DSLR’s digital screen will display the aperture size, as well.

 

The smaller the f-number, the larger the aperture (hole), and consequently, the larger the f-number, the smaller the aperture. Every time you widen up one step (f/5.6 to f/4, for example), you allow in twice the amount of light. Reduce one step, and you let in half the amount of light.

 

The combination of aperture (f-number) and shutter speed determines exposure. Choosing higher f-numbers correspondingly darkens the image that falls on the image sensor, but you can still achieve optimal exposure if you slow shutter speed in proportion.

On the other hand, you can also achieve optimal exposure by choosing a lower f-number and a faster shutter speed. In other words, there are many combinations of aperture and shutter speed that will produce the same exposure. For example, suppose the subject will be correctly exposed at an aperture of f/4 and a shutter speed of 1/250 s. The correct exposure will then also be achieved if you increase the f-number to f/5.6 while slowing shutter speed to 1/125 s. The same is true at f/8 and 1/60 s and at f/11 and 1/30 s.

Combinations of aperture and shutter speed that will produce the same exposure as f/4, 1/250 s

 

Aperture

F16

F11

F8

F5.6

F4

F2.8

F2

F1.4

Shutter speed(seconds)

1/15 1/30 1/60 1/125 1/250 1/500 1/1000 1/2000

 

If you always adjust shutter speed to match any changes in aperture, you can achieve correct exposure at any aperture or shutter speed. Note, however, that changing aperture also changes depth of field, while changing shutter speed alters the appearance of moving objects. In other words, you can also adjust aperture for depth of field or shutter speed to produce the effect of motion.

*The distance in front of and behind the focus point that appears to be in focus is referred to as “depth of field.”

 

High f-number, slow shutter speed

The slow shutter speed blurs the jets of water in the fountain;
the high f-number increases depth of field, bringing the background into focus.

Low f-number, fast shutter speed

The fast shutter speed appears to stop the water in its tracks;
the low f-number reduces depth of field, blurring the background.


Explain Numbers on lens which read… ‘90mm/ f-1:2.8 ED / Ǿ67mm’

There are lots of numbers and letters on lenses, but what do they mean? It’s actually not that difficult to understand, so allow me to break it down for you.

Numbers and Letters on Lenses

 

What does 18-55mm mean?

This refers to the focal length of your lens. 18mm is wide angle, and 55mm is more zoomed. When you zoom your lens in, you’re zooming between 18mm and 55mm. The ‘mm’ stands for millimeter, and this is the distance between your camera’s sensor, and the point of convergence in the lens.

 

The further away the point of convergence is from the sensor, the more zoomed you will be.

 

What does 1:3.5-5.6 mean?

This indicates the maximum aperture of your lens, which is how wide it will go, and ultimately how much light it will allow in. When the number is lower, it allows more light in.

Sometimes you will see lenses which say 1:2.8. This means that the lens will allow a maximum aperture of f/2.8 throughout the whole zoom range.

 

When there is a hyphen, such as 3.5-5.6, this means that the more you zoom, the narrower the aperture will go. When you’re at 18mm, your maximum aperture will be f/3.5, but as you zoom, this aperture will slowly narrow, until you reach 55mm, at which point it will only allow and aperture of f/5.6.

 

The reason the number is a ratio (1:), is because aperture is measured as a ratio.

What does Ø52mm mean?

That symbol of the circle with a line through it is the diameter symbol. In this case, it’s the diameter of the end of your lens (that’s the width of the lens for anyone who’s a little rusty on their math).

 

This number is important to know for any lens caps or filters you buy for the lens, as you want to make sure you buy one that fits.

 

 

What does Macro 1:2 / 1:1 mean?

Technically speaking, your lens is a macro lens when the 1:1 ratio is displayed. It means that whatever you’re taking a photo of is going to be the same size on your camera sensor.

That said though, you will still often see Macro 1:2 listed. This isn’t technically macro, but it will be better than your standard lens, and you typically find this at longer focal lengths on a telephoto lens. It means that whatever you’re taking a photo of will be half its actual size on the camera’s sensor.

 

What does HSM / USM mean?

They mean hypersonic motor and ultrasonic motor. They’re basically the same thing, named differently for different brands.

They’re silent wave motors which focus very quickly and quietly. This might not sound like much, but they have proven to be a real asset to me in the past.

 

What does II mean?

This means that it’s the second version of that particular lens. It’s quite common practice for lens manufacturers to take a very popular lens, and find a way to improve it further, usually with better optics, and/or an image stabiliser. This means that they can sell it again, and make more money.

So when you see II on a lens, it’s the updated version of the lens, and this is probably the one you will want to buy.


Explain how megapixel plays a role in image size.

Camera manufacturers are fond of advertising cameras by the number of megapixels they have. But what exactly is a megapixel and how does it affect photos?

 

What are Pixels? The word Pixel is a shortened and combined version of the words Picture and Element. Every digital camera contains a device called the image sensor which has millions of light capturing cells. The light captured at each cell location is called a digital camera pixel. For the record, there are one million pixels in a megapixel.

 

The Picture on the left shows a portion of picture on right, with the pixels greatly magnified and exaggerated so that you can see how pixels form an image. However, there will be thousands or millions more pixels in an area equivalent to picture on left when you take your pictures.

A megapixel is 1 million pixels. Pixels are small squares that are put together like pieces of a puzzle or mosaic to create your photographs. The resolution of your image will be determined in large part by how many of these tiny squares are packed together in a small space.

 

An 8 megapixel camera (8MP) would have roughly eight million tiny squares of information per inch while a camera phone at 1.5 megapixels (1.5MP) would only have one and a half millions squares of information in an inch.

 

So what does that mean for your photos?

Simply put, the more information the better. The more information squeezed into an area, the better our eyes blend the edges together to create a complete image. If too little information is available the eye will notice the jagged edges of the pixels where they meet, just as you see the individual squares of mosaic tile designs. The accepted “standard” for printing images is currently 300dpi (dots per inch). While dots per inch aren’t technically the same as pixels per inch the difference won’t affect you in your day to day photo taking/printing.

 

How much information do I need?

To figure out how much information you need for a specific print size all you need do is multiply the print size by the resolution desired.

 

For example, with the 300dpi rule in mind, to print an 8×10 photo you would need 2400 pixels by 3000 pixels of information. If you were displaying an image on the internet (where 72 pixels per inch is acceptable) you would only need 576 pixels by 720 pixels.

 

The larger sensors found in Digital SLR cameras produce larger pixels which leads to higher quality images. However, the image sensors found in cameras with smaller sensors can with produce great images that are more than acceptable for the average photographer.

 

The only difference between the highlighted area in picture 1A and whole area of picture 1B is that the individual pixels cannot be seen in picture 1A. The colors and light intensity for each of the millions of pixels in digital images appear to be blended together when we view them as a printed picture or on a computer screen. ​

 

Image File Size: The file size of an image is expressed by the total number of pixels in the width and height of an image. For instance a file size might be written as 3,456 X 2,304. That means there are 3,456 pixels in each row of pixels in the image from left to right, and 2,304 pixels in each column of pixels from top to bottom.

 

To find the total number of pixels in an image, just multiply the number of pixels in the width of the image by the number of pixels in the height of the image. (3,456 X 2,304=7,962,624 ) Usually the total amount of pixels is rounded up or down to the nearest megapixel. So in this case the image might be called an 8 Megapixel picture although it does not contain a full 8 million pixels.

 

Although digital cameras are often marketed with emphasis on the total number of megapixels available for an image, they all have settings which allow the photographer to take pictures with smaller file sizes. That feature can save space on your cameras memory or in your computer hard drive.

 

Also, images with smaller file sizes are easier to send and download when using email or social media. Taking pictures at different file sizes will make more sense as you continue to read about image resolution and print sizes.

 

If the pictures you have already taken are large files, many photo editing programs have functions which allow you to reduce the size of an image file. Adobe Photoshop Elements is the best known photo editing software from which you can change file sizes as well as enhance and/or fix your images.

 

Image Resolution: In general terms, image resolution refers to the amount of digital information contained in an image file. A picture file size of 4,000 x 3,000 pixels will have a higher image resolution than a file size of 2,000 x 1,500 pixels. Higher resolution pictures will be sharper, clearer, and colors will be more accurately reproduced when viewed on a screen or as a print.

 

More specifically, image resolution refers to pixel density in terms of Pixels Per Inch (PPI) rather than the size of the whole image file. PPI is the number of pixels contained in one square inch of an image file. Computer screens are able to show clear and sharp images at low screen resolutions such as 72 PPI or 96 PPI.

 

If you will be taking pictures that are intended for on screen viewing only, you can set your camera to a low resolution setting like 2 or 3 megapixels. The images will look fine on a computer screen. Taking your pictures at a higher quality setting like 14 megapixels will not make the image look better on a 72 PPI computer screen.

 

On the other hand, it is absolutely necessary to set your camera to one of its highest quality settings if you are going to make enlarged prints of your images on photo paper. A picture taken at a 2 megapixel setting will make a very poor quality 11 X 14 size printed picture. If you have a 14 megapixel camera and know that you will be making enlarged prints from your images, use the higher 14 megapixel setting to ensure that you will get the best quality prints.

 


What is a film or image sensor format? Discuss on various formats. What is half frame or crop sensor?


In digital photography, the image sensor format is the shape and size of the image sensor.

The image sensor format of a digital camera determines the angle of view of a particular lens when used with a particular sensor. Because the image sensors in many digital cameras is smaller than the 24 mm × 36 mm image area of full-frame 35-mm cameras, a lens of a given focal length will give a narrower field of view on such cameras.

The size of a sensor is often expressed as optical format in inches. Other measures are also used; see table of sensor formats and sizes below.

Lenses produced for 35-mm film cameras may mount well on the digital bodies, but the larger image circle of the 35-mm system lens allows unwanted light into the camera body, and the smaller size of the image sensor compared to 35-mm film format results in cropping of the image. This latter effect is known as field of view crop. The format size ratio (relative to the 35-mm film format) is known as the field of view crop factor, crop factor, lens factor, focal length conversion factor, focal length multiplier or lens multiplier.

 

Why is camera image sensor size important?

The size of sensor that a camera has ultimately determines how much light it uses to create an image. In very simple terms, image sensors (the digital equivalent of the film your father might have used in his camera) consist of millions of light-sensitive spots called photosites which are used to record information about what is seen through the lens. Therefore, it stands to reason that a bigger sensor can gain more information than a smaller one and produce better images.

 

Think about it this way, if you had a compact camera with a typically small image sensor, its photosites would be dwarfed by those of a DSLR with the same number of megapixels, but a much bigger sensor. Able to gain more information, the large DSLR photosites would be capable of turning out photos with better dynamic range, less noise and improved low light performance than its smaller-sensored sibling. Which as we know, makes for happy photographers.

 

Larger sensors also allow manufacturers to increase the resolution of their cameras – meaning they’re able to produce more detailed images – without sacrificing too much in terms of other image quality attributes. For example, a Full Frame camera with 36 megapixels would have very similar sized pixels to an APS-C camera with 16 megapixels.

 

Digital Camera Sensor Size Comparison

Many digital cameras are commercially available on the market right now, and they all have a wide range of sensor sizes. And while it’s good to have choices, it can also get pretty confusing, especially to a beginner.

 

We’ve all heard of the full-frame DSLR camera, of course, which is the gear of choice of seasoned professional photographers. For enthusiasts and beginners, the usual choice is the APS-C format or crop-sensor DSLR camera. However, some prefer to use mirrorless cameras or MILCs, which are the smaller, lighter versions of DSLRs. Lastly, there are the 1-inch sensor cameras, which are better known as point-and-shoot or compact digital cameras.

 

There’s also the medium-format cameras—the lesser known of the group. These cameras have the largest sensors out of all the available digital cameras for photography, which means they can get pretty expensive. The cheapest medium-format digital camera that is currently on the market (the Mamiya 645DF) costs up to about $6,000, making this type of camera exclusive to hardcore pros.

Camera Sensor Size Comparison Table

Keep in mind that camera sensor formats are not standardized across the different brands or models, so dimensions may vary slightly from the figures listed above.

Here is a diagram to help you visualize the size difference between the most common camera sensor types:

Digital Camera Sensor Types

 

Medium Format

Medium format is the largest sensor type in digital cameras for photographic applications. However, it doesn’t come in just one size. Medium format has its own group of sensors, with its own equivalents to the four thirds, APS-C, and full-frame formats. There are a variety of sensor sizes for medium-format cameras, and typical sizes range from around 43.8×32.9mm to 53.7×40.2mm.

 

Due to their large image sensors, medium-format DSLR cameras are traditionally heavier and bulkier than their full-frame counterparts. But that may be about to change, as brands like Hasselblad have recently come out with smaller mirrorless medium-format cameras like the X1D to provide photographers with a lighter, more compact option.

35mm Full-Frame

Full-frame sensors are available in both DSLR and mirrorless cameras. They have the same dimensions as the 35mm film, hence the name. This sensor type is considered the gold standard among professional photographers who want the highest-quality images.

The dimensions of a 35mm sensor are typically 36×24mm.

APS-H

The first Canon camera to carry the APS-H sensor type was the groundbreaking EOS-1D, which was launched in 2001. The company released four more cameras (all members of the 1D line) with the same sensor type before it was discontinued.

The APS-H is slightly larger than the APS-C sensor format that many Canon DSLR cameras use today but smaller than a traditional full-frame sensor.

APS-C

The APS-C or crop-sensor format is the most well-known and most versatile of the bunch. It’s available in both DSLR and mirrorless cameras and is used by beginners and professionals alike.

 

The typical APS-C sensor size is different across camera brands. Canon APS-C sensors are usually 22.3×14.9mm, while other brands like Nikon, Sony, Pentax, and more usually feature APS-C sensors with 23.6×15.6mm dimensions.

Four Thirds/Micro Four Thirds

Created by Olympus and Panasonic, the Four Thirds System is a standard that allows for the compatibility of lenses and bodies across participating camera makers. Image sensor size is 17.3×13mm with a crop factor of 2.0 when compared to full-frame camera sensors.

For mirrorless cameras, the two companies created the Micro Thirds Format System, which was released in 2008. It shares the Four Thirds System’s sensor size and specifications but uses a compact design with no space for the movable mirror, pentaprism, and other parts of the DSLR mechanisms not found in mirrorless cameras.

 

The Four Thirds System uses a 4:3 image aspect ratio, hence the name. The Micro Four Thirds System uses the same ratio but can also record 16:9, 3:2, and 1:1 formats.

1” Type (and below)

Any sensor that is about 1.5 to 1-inch in size or smaller can be found in non-interchangeable lens cameras (your typical point and shoot) and smartphone cameras.

 

High-end compact cameras like the Panasonic Lumix DMC-FZ1000 and the Sony Cyber-Shot DSC-RX10 III use 1-inch sensors, allowing these cameras to produce good results—in terms of image and video quality—that you won’t get with regular point-and-shoot cameras.

When it comes to sensor sizes, the two terms most used to classify them are “full frame” and “crop sensor”. The term “full frame” refers to a sensor size that has the same dimensions as the 35mm film format. Why is 35mm format considered to be the standard or a “full frame”? Well, the 35mm film format has been the standard in film gauge since 1909 due to its balance in cost and image quality and has stuck ever since. So which sensor type is the best fit for your photography?

 

Difference Between Full Frame And Crop Sensor

A crop sensor refers to any sensor smaller than a full frame sensor or a 35mm film frame. The common types of crop sensor include APS-C and micro 4/3 systems. Aside from the difference in physical size of the sensor, there are several other differences between a crop sensor and a full frame sensor.

Full Frame vs. Crop Sensor Field of View and Focal Length

The most visible difference between full frame and crop sensor is their field of view. In fact the term “crop” implies just exactly that. The smaller sensor’s field of view is a crop of the full frame. This means that if a full frame DSLR like a Nikon D800 and a crop-sensor DSLR like a Nikon D7100 take the same photo from the same distance, with the same lens and point of view, the D7100 will capture a tighter field of view than the D800.

Focal length measurements on lenses are based on the 35mm standard. If you are using a crop frame camera the sensor is cropping out the edges of the frame, which is effectively increasing the focal length. The amount of difference in the field of view or focal length with a crop sensor is measured by its “Multiplier.”

 

For example, a Nikon APS-C crop sensor has a 1.5x multiplier. When a Nikon 50mm f/1.4 lens is attached to that Nikon DSLR, the focal length is multiplied by 1.5x and effectively acts like a 75mm lens on a full frame DSLR.


Which situations suit for intentional wrong colour temperature?

What the…. I dont know the answer to this question. Please revert on mail.


Suggest photographic occasions where wrong exposure is most appropriate exposure

..hecc? I dont know the answer to this question. Please revert on mail.


Derivatives: 7/8 marks (Mini case study)

1. For an ‘Exposure Value’ f-5.6 & shutter speed 1/8, (ISO 100) what will be the new combination of Aperture & Shutter for shallowest Depth of Field?’ (Lens- 150mm f-2.8). Use thumb rule to consider safe shutter speed.

I dont know the Answer to this one.


2. For an ‘Exposure Value’ f-8 & shutter speed 1/30, what will be the new combination of Aperture & Shutter for sure-shot Motion Freeze?’ (Lens- 85mm f-2) (ISO-100)

 

[ EV or Exposure Value is what the camera’s meter has suggested for correct exposure. This can give perfectly exposed pictures in most of the situations. A creative photographer has to make a successful picture of his visualization as well as foolproof result. He need not rely on camera decision about exposure]

 

Solution

 

Given

 

Aperture f8

Shutter 1/30

Lens 85mm f-2  [ i.e. this lens has a fixed focal length and maximum opening of f-2 ]

Condition Guaranteed Motion Freeze

 

Motion Freeze depends on many circumstances such as

  • Subject Speed
  • Subject Distance
  • Subject Direction
  • Focal Length
  • Shutter Speed

 

Here we have to consider, only shutter speed for a given focal length as other things are not given

 

So, the Condition states that the shutter speed to be increased to maximum permissible..

 

Shutter Aperture Reason
30 8 EV as per camera metering (given)
60 5.6 One increment towards higher speed need opening of aperture with one stop
125 4 Same xD
250 2.8 Same as above lmao
500 2 This is the highest shutter-speed permissible as lens cannot open beyond f-2 on the given lens
500 2 New Combination

So, f-2 @ 1/500 is the New Combination to get Motion Freeze.

Also this compiles with the thumb rule for safe shutter speed.

SS>2F; i.e. Shutter Speed has to be greater than twice the focal length to get Shakefree Pictures of Moving Objects.

I was told this is the answer because this is full stop. 1/320 will be half stop. If there are any changes required, please revert on mail.


Colour Temperature

The color temperature of a light source is the temperature of an ideal black-body radiator that radiates light of a color comparable to that of the light source. Color temperature is a characteristic of visible light that has important applications in lighting, photography, videography, publishing, manufacturing, astrophysics, horticulture, and other fields. In practice, color temperature is meaningful only for light sources that do in fact correspond somewhat closely to the radiation of some black body, i.e., those on a line from reddish/orange via yellow and more or less white to blueish white; it does not make sense to speak of the color temperature of, e.g., a green or a purple light. Color temperature is conventionally expressed in kelvin, using the symbol K, a unit of measure for absolute temperature.

Color temperatures over 5000 K are called “cool colors” (bluish white), while lower color temperatures (2700–3000 K) are called “warm colors” (yellowish white through red). “Warm” in this context is an analogy to radiated heat flux of traditional incandescent lighting rather than temperature. The spectral peak of warm-coloured light is closer to infrared, and most natural warm-coloured light sources emit significant infrared radiation. The fact that “warm” lighting in this sense actually has a “cooler” color temperature often leads to confusion.


Shutter

In photography, a shutter is a device that allows light to pass for a determined period, exposing photographic film or a light-sensitive electronic sensor to light in order to capture a permanent image of a scene. A shutter can also be used to allow pulses of light to pass outwards, as seen in a movie projector or a signal lamp. A shutter of variable speed is used to control exposure time of the film. The shutter is so constructed that it automatically closes after a certain required time interval. The speed of the shutter is controlled by a ring outside the camera, on which various timings are marked.

 

Adjustable shutters control exposure time, or the length of time during which light is admitted. Optimum exposure time varies according to lighting conditions, movement of the subject, and other factors, and it may be either selected in advance by the photographer or, in the case of automatic cameras, set by the camera itself on a signal from a built-in exposure-metering system. The mechanical shutter can usually be set only for indicated speeds throughout its range; some electronic shutters have a continuous operating range.

The aperture and shutter-speed combinations shown below allow the same amount of light to enter the camera but result in different images. Smaller apertures extend the zone of sharp focus, and slow shutter speeds show blurred movement.Encyclopædia Britannica, Inc.

 

Modern camera shutters are of two principal types.

The leaf shutter, positioned between or just behind the lens components, consists of a number of overlapping metal blades opened and closed either by spring action or electronically.

 

The focal-plane shutter, located directly in front of the image plane, consists of a pair of overlapping blinds that form an adjustable slit or window; driven mechanically by spring or electronically, the slit moves across the film in one direction, exposing the entire frame in its sweep. The width of the slit determines exposure time; the narrower the slit, the shorter the exposure. The actual travel time is fairly constant for all exposure times; a mechanism triggers the release of the second blind. Exposures as brief as 1/12,000 of a second are possible with the focal-plane shutter.

 

Most digital cameras also employ mechanical shutters, though some, especially small “point and shoot” cameras and cell-phone cameras, use electronic “shutters” that briefly turn off the light-reading capability of the image sensor so that the captured image can be stored and the sensor cleared for the next exposure. The use of mechanical shutters in higher-quality digital cameras allows more sensor capacity to be used for gathering and storing the image, thus improving the quality of the photograph. Some digital cameras feature the combined action of both mechanical and electronic shutters.


Light/ Exposure meter

 

Use of a Light meter for portrait cinematography in a Turkish music video set

A light meter is a device used to measure the amount of light. In photography, a light meter is often used to determine the proper exposure for a photograph. Typically a light meter will include either digital or analog electronic circuit, which allows the photographer to determine which shutter speed and f-number should be selected for an optimum exposure, given a certain lighting situation and film speed.

 

Light meters are also used in the fields of cinematography and scenic design, in order to determine the optimum light level for a scene. They are used in the general field of architectural lighting design to verify proper installation and performance of a building lighting system, and in assessing the light levels for growing plants.

 

These are two terms that are usually used interchangeably by photographers. Both are devices for measuring light, however, technically a “light meter” only reports the light’s intensity, whereas an exposure meter measures the intensity of light and translates that data into camera settings needed to make a correct exposure in the given lighting situation. There are two types of exposure meters – incident and reflective. The exposure meter built into your camera is a reflective light meter, meaning that it measures light reflected from a subject. The other type of exposure meter, incident, measures light that falls directly onto the meter. This is the type of meter that is used to measure flash’s intensity.


White balance

White Balance is an aspect of photography that many digital camera owners don’t understand or use – but it’s something well worth learning about as it can have a real impact upon the shots you take. At its simplest, the reason we adjust white balance is to get the colors in your images as accurate as possible.

 

You might have noticed when examining shots after taking them that at times images can come out with an orange, blue, yellow etc look to them – despite the fact that to the naked eye the scene looked quite normal. The reason for this is that images different sources of light have a different ‘color’ (or temperature) to them. Fluorescent lighting adds a bluish cast to photos whereas tungsten (incandescent/bulbs) lights add a yellowish tinge to photos.

The range in different temperatures ranges from the very cool light of blue sky through to the very warm light of a candle. We don’t generally notice this difference in temperature because our eyes adjust automatically for it. So unless the temperature of the light is very extreme a white sheet of paper will generally look white to us. However a digital camera doesn’t have the smarts to make these adjustments automatically and sometimes will need us to tell it how to treat different light.


Adjusting White Balance

Different digital cameras have different ways of adjusting white balance so ultimately you’ll need to get out your camera’s manual out to work out the specifics of how to make changes. Having said this – many digital cameras have automatic and semi-automatic modes to help you make the adjustments.

 

Here are some of the basic White Balance settings you’ll find on cameras:

  • Auto – this is where the camera makes a best guess on a shot by shot basis. You’ll find it works in many situations but it’s worth venturing out of it for trickier lighting.
  • Tungsten – this mode is usually symbolized with a little bulb and is for shooting indoors, especially under tungsten (incandescent) lighting (such as bulb lighting). It generally cools down the colors in photos.
  • Fluorescent – this compensates for the ‘cool’ light of fluorescent light and will warm up your shots.
  • Daylight/Sunny – not all cameras have this setting because it sets things as fairly ‘normal’ white balance settings.
  • Cloudy – this setting generally warms things up a touch more than ‘daylight’ mode.
  • Flash – the flash of a camera can be quite a cool light so in Flash WB mode you’ll find it warms up your shots a touch.
  • Shade – the light in shade is generally cooler (bluer) than shooting in direct sunlight so this mode will warm things up a little.

Manual White Balance Adjustments

In most cases you can get a pretty accurate result using the above preset white balance modes – but some digital cameras (most DSLRs and higher end point and shoots) allow for manual white balance adjustments also. The way this is used varies a little between models but in essence what you do is to tell your camera what white looks like in a shot so that it has something as a reference point for deciding how other colors should look. You can do this by buying yourself a white (or grey) card which is specifically designed for this task – or you can find some other appropriately colored object around you to do the job.

 

The first shot is one of some books on my wife’s bookshelf taken in Auto White Balance mode. The light in my room is from three standard light bulbs and as a result the image is quite warm or yellow.

After taking this picture I then held up a piece of white paper to my camera to tell it what color white is. Then I took a second shot with this setting and got the following result – which you’ll see is a much truer color cast than the first image.

This manual adjustment is not difficult to do once you find where to do it in the menu on your camera and it’s well worth learning how to do it.


SLR

 

The historic Zeiss Ikon VEB Contax S, manufactured in Dresden, one of the two original pentaprism SLRs for eye-level viewing that went into production in 1949. The Italian Rectaflex offered its first production SLR, the series 1000, the same year.

 

A single-lens reflex camera (SLR) is a camera that typically uses a mirror and prism system (hence “reflex” from the mirror’s reflection) that permits the photographer to view through the lens and see exactly what will be captured. With twin lens reflex and rangefinder cameras, the viewed image could be significantly different from the final image. When the shutter button is pressed on a mechanical SLR, the mirror flips out of the light path, allowing light to pass through to the light receptor and the image to be captured.

 

Many of the advantages of SLR cameras derive from viewing and focusing the image through the attached lens. Most other types of cameras do not have this function; subjects are seen through a viewfinder that is near the lens, making the photographer’s view different from that of the lens. SLR cameras provide photographers with precision; they provide a viewing image that will be exposed onto the negative exactly as it is seen through the lens. There is no parallax error, and exact focus can be confirmed by eye—especially in macro photography and when photographing using long focus lenses. The depth of field may be seen by stopping down to the attached lens aperture, which is possible on most SLR cameras except for the least expensive models. Because of the SLR’s versatility, most manufacturers have a vast range of lenses and accessories available for them.

However it also comes with a few disadvantages. In most cases, single-lens reflex cameras cannot be made as small or as light as other camera designs—such as rangefinder cameras, autofocus compact cameras and digital cameras with electronic viewfinders (EVF)—owing to the mirror box and pentaprism/pentamirror. The mirror box also prevents lenses with deeply recessed rear elements from being mounted close to the film or sensor unless the camera has a mirror lockup feature; this means that simple designs for wide angle lenses cannot be used. Instead, larger and more complex retrofocus designs are required.


Panning

When you pan you’re moving your camera in synchronicity with your subject as it moves parallel to you.  Still a little wordy huh? It’s not as complicated as it sounds. Shake your head “no.” Go on and do it. Now cut that in half and pretend like you’re moving you head along with a cheetah as is it flies by and you’ve got the idea. In order to pan successfully your camera has got to follow the subject’s movement and match it’s speed and direction as perfectly as possible.

 

Proper panning implies motion. However, panning creates the feeling of motion and speed without blurring the subject as a slow shutter speed sans panning would tend to do.  Take for example the two images below. The first is an example of panning. Notice how the car is clear and crisp but the rest of the image is blurred to show the motion of the vehicle.  This effect was achieved by panning.

Now check out the second image.  This is an example of a slow shutter speed (which panning also requires by the way) without the panning of the camera.  Because the camera was held static, the moving object, in this case the train, depicts the motion while the area around it is static.

Is one image better than the other?  Maybe, maybe not, it’s certainly a matter of preference. Both static shots employing slow shutter speeds and panning images have their place and time and it’s up to you as the discerning photographer to decide which you’d like to employ in any given situation.

 

When photographing a moving subject, the panning technique is achieved by keeping the subject in the same position of the frame for the duration of the exposure. The length of the exposure must be long enough to allow the background to blur due to the movement of the camera as the photographer follows the subject in the viewfinder.

 

The exact length of exposure required will depend on the speed at which the subject is moving, the focal length of the lens and the distance from the subject and background. An F1 car speeding along a straight might allow the photographer to achieve a blurred background at 1/250 second, while the photographer might need to go as slow as 1/40 to achieve the same amount of blur for a picture of a running man.

WINNER WINNER
CHICKEN DINNER
[ no hate for vegans ]
{no love either… jk}

The faster shutter speed allowed by fast moving subjects are easier to capture in a smoothly panned shot. With slower moving subjects, the risk is that the panning motion will be jerky, and it is also harder to keep the subject in the same position of the frame for the longer period of time.

 

To aid in capturing panned pictures, photographers use aids such as tripods and monopods, which make it easy to swing the camera along one plane, while keeping it steady in the others.


Star trails

A star trail is a type of photograph that uses long-exposure times to capture the apparent motion of stars in the night sky due to Earth’s rotation. A star-trail photograph shows individual stars as streaks across the image, with longer exposures resulting in longer arcs. Typical exposure times for a star trail range from 15 minutes to several hours, requiring a “Bulb” setting on the camera to open the shutter for a period longer than usual.

Star trails have been used by professional astronomers to measure the quality of observing locations for major telescopes.

 

Star trail photographs are captured by placing a camera on a tripod, pointing the lens toward the night sky, and allowing the shutter to stay open for a long period of time. Star trails are considered relatively easy for amateur astrophotographers to create. Photographers generally make these images by using a SLR camera with its lens focus set to infinity. A cable release allows the photographer to hold the shutter open for the desired amount of time. Typical exposure times range from 15 minutes to many hours long, depending on the desired length of the star trail arcs for the image.

Even though star trail pictures are created under low-light conditions, long exposure times allow fast films, such as ISO 200 and ISO 400. Wide-apertures, such as f/5.6 and f/4, are recommended for star trails.

Because exposure times for star trail photographs can be several hours long, camera batteries can be easily depleted. Mechanical cameras that do not require a battery to open and close the shutter have an advantage over more modern film and digital cameras that rely on battery power. On these cameras, the Bulb, or B, exposure setting keeps the shutter open. Another problem that digital cameras encounter is an increase in detector noise with increasing exposure time.


Bokeh

In photography, bokeh is the a e s t h e t i c quality of the blur produced in the out-of-focus parts of an image produced by a lens. Bokeh has been defined as “the way the lens renders out-of-focus points of light”. Differences in lens aberrations and aperture shape cause some lens designs to blur the image in a way that is pleasing to the eye, while others produce blurring that is unpleasant or distracting—”good” and “bad” bokeh, respectively. Bokeh occurs for parts of the scene that lie outside the depth of field. Photographers sometimes deliberately use a shallow focus technique to create images with prominent out-of-focus regions.

Bokeh is often most visible around small background highlights, such as specular reflections and light sources, which is why it is often associated with such areas. However, bokeh is not limited to highlights; blur occurs in all out-of-focus regions of the image.

 

The term comes from the Japanese word boke (暈け or ボケ), which means “blur” or “haze”, or boke-aji (ボケ味), the “blur quality”. The Japanese term boke is also used in the sense of a mental haze or senility.[7] The term bokashi (暈かし) is related, meaning intentional blurring or gradation.

Though difficult to quantify, some lenses have subjectively more pleasing out-of-focus areas. “Good” bokeh is especially important for macro lenses and long telephoto lenses, because they are typically used in situations that produce shallow depth of field. Good bokeh is also important for medium telephoto lenses (typically 85–150 mm on 35 mm format). When used in portrait photography (for their “natural” perspective), the photographer usually wants a shallow depth of field, so that the subject stands out sharply against a blurred background.

Lenses with 11, 12, or 15 blade iris diaphragms are often claimed to excel in bokeh quality. Because of this, the lenses do not need to reach wide apertures to get better circles (instead of polygons). In the past, wide aperture lenses (f/2, f/2.8) were very expensive, due to the complex mathematical design and manufacturing know-how required, at a time when all computations and glass making were done by hand. Leica could reach a good bokeh at f/4.5. Today it is much easier to make an f/1.8 lens, and a 9-bladed lens at f/1.8 is enough for an 85mm lens to achieve great bokeh.

Related image

Almost a Bokeh


Focal length & Image

The focal length of an optical system is a measure of how strongly the system converges or diverges light. For an optical system in air, it is the distance over which initially collimated (parallel) rays are brought to a focus. A system with a shorter focal length has greater optical power than one with a long focal length; that is, it bends the rays more sharply, bringing them to a focus in a shorter distance.

 

In most photography and all telescopy, where the subject is essentially infinitely far away, longer focal length (lower optical power) leads to higher magnification and a narrower angle of view; conversely, shorter focal length or higher optical power is associated with lower magnification and a wider angle of view. On the other hand, in applications such as microscopy in which magnification is achieved by bringing the object close to the lens, a shorter focal length (higher optical power) leads to higher magnification because the subject can be brought closer to the center of projection.

 

 

28 mm lens 50 mm lens 70 mm lens 120 mm lens

An example of how lens choice affects angle of view.
The photos above were taken by a 35 mm camera at a fixed distance from the subject.

 

Camera lens focal lengths are usually specified in millimetres (mm), but some older lenses are marked in centimetres (cm) or inches.

 

Focal length (f) and field of view (FOV) of a lens are inversely proportional. For a standard rectilinear lens, FOV = 2 arctan x/2f, where x is the diagonal of the film.

 

When a photographic lens is set to “infinity”, its rear nodal point is separated from the sensor or film, at the focal plane, by the lens’s focal length. Objects far away from the camera then produce sharp images on the sensor or film, which is also at the image plane.

 

To render closer objects in sharp focus, the lens must be adjusted to increase the distance between the rear nodal point and the film, to put the film at the image plane. The focal length (f), the distance from the front nodal point to the object to photograph (s1), and the distance from the rear nodal point to the image plane (s2) are then related by:

 

The focal length of a lens determines the magnification at which it images distant objects. It is equal to the distance between the image plane and a pinhole that images distant objects the same size as the lens in question. For rectilinear lenses (that is, with no image distortion), the imaging of distant objects is well modelled as a pinhole camera model. This model leads to the simple geometric model that photographers use for computing the angle of view of a camera; in this case, the angle of view depends only on the ratio of focal length to film size. In general, the angle of view depends also on the distortion.


Special Purpose Lenses

If an Elaborate Version Update is required, lemme know

  • A tilt/shift lens, set to its maximum degree of tilt relative to the camera body.
  • Apochromat (APO) lenses have added correction for chromatic aberration.
  • Process lenses have extreme correction for aberrations of geometry (pincushion distortion, barrel distortion) and are generally intended for use at a specific distance.
  • Process and apochromat lenses are normally of small aperture, and are used for extremely accurate photographs of static objects. Generally their performance is optimized for subjects a few inches from the front of the lens, and suffers outside this narrow range.
  • Enlarger lenses are made to be used with photographic enlargers (specialised projectors), rather than cameras.
  • Lenses for aerial photography.
  • Fisheye lenses: extreme wide-angle lenses with an angle of view of up to 180 degrees or more, with very noticeable (and intended) distortion.
  • Stereoscopic lenses, to produce pairs of photographs which give a 3-dimensional effect when viewed with an appropriate viewer.
  • Soft-focus lenses which give a soft, but not out-of-focus, image and have an imperfection-removing effect popular among portrait and fashion photographers.
  • Infrared lenses
  • Ultraviolet lenses
  • Swivel lenses rotate while attached to a camera body to give unique perspectives and camera angles.
  • Shift lenses and tilt/shift lenses (collectively perspective control lenses) allow special control of perspective on SLR cameras by mimicking view camera movements.

Image formats (file)

Each of image file types has their own pros and cons. They were created for specific, yet different, purposes. What’s the difference, and when is each format appropriate to use?

Let us tackle the five most common image formats for the web and computer graphics: JPEG, GIF, BMP, TIFF and PNG.

 

JPEG

JPEG is short for Joint Photographic Experts Group, and is the most popular among the image formats used on the web. JPEG files are very ‘lossy’, meaning so much information is lost from the original image when you save it in a JPEG file. This is because JPEG discards most of the information to keep the image file size small; which means some degree of quality is also lost.

 

Original File:


JPEG Medium Compressed File:

As shown above, image compression is not that evident at first glance. But if you take a closer look, the JPEG image is not as sharp as the original image. The colors are paler and the lines are less defined and the picture is noisier. If you zoom in there are JPEG artifacts like any other JPEG files.

JPEG compression of varying levels, from highest to lowest.

 

Almost every digital camera can shoot and save in the JPEG format. JPEG is very web friendly because the file is smaller, which means it takes up less room, and requires less time to transfer to a site. Moreover it is less grainy then GIF, the old king of the internet roost. Since 1994, JPEG has been considered the standard.

 

Pros of JPEG:

  • 24-bit color, with up to 16 million colors
  • Rich colors, great for photographs that need fine attention to color detail
  • Most used and most widely accepted image format
  • Compatible in most OS (Mac, PC, Linux)

Cons of JPEG:

  • They tend to discard a lot of data
  • After compression, JPEG tends to create artifacts
  • Cannot be animated
  • Does not support transparency

 

GIF

GIF, short for Graphics Interchange Format, [pronounced as jiff] is limited to the 8 bit palette with only 256 colors. GIF is still a popular image format on the internet because image size is relatively small compared to other image compression types.

 

GIF compresses images in two ways: first, by reducing the number of colors in rich color images, thus reducing the number of bits per pixel. Second, GIF replaces multiple occurring patterns (large patterns) into one. So instead of storing five kinds of blue, it stores only one blue.

GIF is most suitable for graphics, diagrams, cartoons, anime and logos with relatively few colors. GIF is still the chosen format for animation effects.

Compared to JPEG, it is lossless and thus more effective with compressing images with a single color, but pales in detailed or dithered pictures. In other words, GIF is lossless for images with 256 colors and below. So for a full color image, it may lose up to 99.998% of its colors. One edge of the GIF image format is the interlacing feature, giving the illusion of fast loading graphics. When it loads in a browser, the GIF first appears to be blurry and fuzzy, but as soon as more data is downloaded, the image becomes more defined until all the date has been downloaded.

Pros of GIF:

  • Can support transparency
  • Can do small animation effects
  • ‘Lossless’ quality–they contain the same amount of quality as the original, except of course it now only has 256 colors
  • Great for images with limited colors, or with flat regions of color

Cons of GIF:

  • Only supports 256 colors
  • It’s the oldest format in the web, having existed since 1989. It hasn’t been updated since, and sometimes, the file size is larger than PNG.

 

BMP

The Windows Bitmap or BMP files are image files within the Microsoft Windows operating system. In fact, it was at one point one of the few image formats. These files are large and uncompressed, but the images are rich in color, high in quality, simple and compatible in all Windows OS and programs. BMP files are also called raster or paint images.

 

BMP files are made of millions and millions of dots called ‘pixels,’ with different colors and arrangements to come up with an image or pattern. It might be an 8-bit, 16-bit or 24-bit image. Thus when you make a BMP image larger or smaller, you are making the individual pixels larger, and thus making the shapes look fuzzy and jagged. BMP files are not great and not very popular. Being oversized, bitmap files are not what you call ‘web friendly’, nor are they compatible in all platforms and they do not scale well.

 

Pros of BMP:

  • Works well with most Windows programs and OS, you can use it as a Windows wallpaper

Cons of BMP:

  • Does not scale or compress well
  • Again, very huge image files making it not web friendly
  • No real advantage over other image formats

 

TIFF

TIFF was created by Aldus for ‘desktop publishing’, and by 2009 it was transferred to the control of Adobe Systems. TIFF is popular among common users, but has gained recognition in the graphic design, publishing and photography industry. It is also popular among Apple users.

Above is a screenshot of how a TIFF image looks like–TIFF is not compatible for all systems; so to be sure, I uploaded a screenshot in JPEG of a TIFF image preview instead of uploading the original TIFF image here. Notice the crisp quality and rich colors of the photo.

The TIFF image format is easy to use with software that deals with page layout, publishing and photo manipulation via fax, scanning, word processing, etc. TIFF is very flexible, it can be lossy or lossless. TIFF is a rich format and supported by many imaging programs.

It is capable of recording halftone image data with different pixel intensities, thus is the perfect format for graphic storage, processing and printing. This makes TIFF the superior raster image format.

Pros of TIFF:

  • Very flexible format, it supports several types of compression like JPEG, LZW, ZIP or no compression at all.
  • High quality image format, all color and data information are stored
  • TIFF format can now be saved with layers

Cons of TIFF:

  • Very large file size–long transfer time, huge disk space consumption, and slow loading time.

 

PNG

PNG or (Portable Network Graphics) is a recently introduced format, so not everyone is familiar with it. But PNG has been approved as a standard since 1996. It is an image format specifically designed for the web. PNG is, in all aspects, the superior version of the GIF.

Just like the GIF format, the PNG is saved with 256 colors maximum but it saves the color information more efficiently. It also supports an 8 bit transparency.

PNG was actually created for the intent to replace the GIF as an image format that doesn’t require a patent license. PNG can support 24 bit RGB color images, grayscale images, both with and without alpha channels. RGB cannot support CMYK color spaces, and is not designed for print graphics.


ISO

In traditional (film) photography ISO (or ASA) was the indication of how sensitive a film was to light. It was measured in numbers (you’ve probably seen them on films – 100, 200, 400, 800 etc). The lower the number the lower the sensitivity of the film and the finer the grain in the shots you’re taking.

 

In Digital Photography ISO measures the sensitivity of the image sensor. The same principles apply as in film photography – the lower the number the less sensitive your camera is to light and the finer the grain.

 

Higher ISO settings are generally used in darker situations to get faster shutter speeds. For example an indoor sports event when you want to freeze the action in lower light. However the higher the ISO you choose the noisier shots you will get. I’ll illustrate this below with two enlargements of shots – the one on the left is taken at 100 ISO and the one of the right at 3200 ISO

(you can see larger sized images of both shots
here for the 100 ISO and here for the 3200 ISO)

 

100 ISO is generally accepted as ‘normal’ and will give you lovely crisp shots (little noise/grain).

 

Most people tend to keep their digital cameras in ‘Auto Mode’ where the camera selects the appropriate ISO setting depending upon the conditions you’re shooting in (it will try to keep it as low as possible) but most cameras also give you the opportunity to select your own ISO also.

 

When you do override your camera and choose a specific ISO you’ll notice that it impacts the aperture and shutter speed needed for a well exposed shot. For example – if you bumped your ISO up from 100 to 400 you’ll notice that you can shoot at higher shutter speeds and/or smaller apertures.

 

Digital cameras have far surpassed film in terms of sensitivity to light, with ISO equivalent speeds of up to 4,560,000, a number that is unfathomable in the realm of conventional film photography. Faster processors, as well as advances in software noise reduction techniques allow this type of processing to be executed the moment the photo is captured, allowing photographers to store images that have a higher level of refinement and would have been prohibitively time consuming to process with earlier generations of digital camera hardware.

 

Zoom lens

 

A true zoom lens, also called a parfocal lens, is one that maintains focus when its focal length changes. A lens that loses focus during zooming is more properly called a varifocal lens. Despite being marketed as zoom lenses, virtually all consumer lenses with variable focal lengths use varifocal design.

 

The convenience of variable focal length comes at the cost of complexity – and some compromises on image quality, weight, dimensions, aperture, autofocus performance, and cost. For example, all  zoom lenses suffer from slight, loss of image resolution at their maximum aperture, especially at the extremes of their focal length range. This effect is evident in the corners of the image, when displayed in a large format or high resolution. The greater the range of focal length a zoom lens offers, the more exaggerated these compromises must become.

 

Zoom lenses are the lenses with variable focal lengths. In these lenses the positive and negative elements of the lens are put together in such a way that by moving them you can get varied focal lengths. A zoom lens could “zoom” from a short (wide-angle) to long (“telephoto”) focal length, making things look bigger and closer as you zoom in. Or it could zoom from an extreme wide-angle to a moderate wide-angle, never coming close to a “telephoto” focal length. Or any other range of focal lengths.

 

A 300mm lens is a telephoto but is not a zoom because 300mm is high mm (in other words, ‘long focal length’ or ‘zoomed in’) but it does not cover a range of focal lengths. (You can only use that lens at 300mm, not 299 mm or 472674mm) Insead, we call these lenses prime lenses. A prime lens does not cover a range of focal lengths, just one.

 

A 10-20mm lens is not a telephoto lens but is a zoom lens. It is not zoomed in at all. It has a short focal length, low mm. It’s called wide angle. If you felt like it, you could shoot at 15mm when you feel jumpy and 16mm when you feel bumpy. You could not, however shoot at a high focal length as you could with the 300mm lens


Field Camera Movements

I do not hath the answer


Exposure Triangle

The exposure triangle is a common way of associating the three variables that determine the exposure of a photograph: aperture, shutter speed, and ISO. One must balance all three of these to achieve a desired result, an adjustment of one requiring adjustments of at least one of the others. They do not only affect exposure, but are also the largest determiners of the global appearance of an image; thus, their mastery is absolutely crucial both for technique and composition.

These three things work together to expose your picture perfectly, and after experimenting for a while, you may even find that you can use your knowledge of these three things to manipulate your picture for different effects.

 

Aperture

The aperture or f-stop is how wide open your lens is. Imagine a hole: if it’s open just a teeny bit, there won’t be very much light coming through. If it’s a big hole, lots of light will come through[now we are talking.]. The tricky thing with aperture is that often confusing numbering system.

 

  • SMALL numbers (like f/1.8) = wide open aperture (large opening).
  • BIG numbers (like f/22) = small aperture (teeny opening).

 

Aperture is a measure of how open or closed the lens’ iris is. A wider aperture (or lower f-number) means more light will be let in by the lens, simply because the opening is larger. A narrower aperture (or higher f-number) allows less light to reach the sensor.

 

You might wonder why we would ever want less light to reach the sensor. The answer the majority of the time is that we want a larger depth of field. Depth of field is a byproduct of aperture. Narrower apertures (higher f-numbers) give a greater depth of field, allowing more of a scene to be in focus (think landscapes). Wider apertures (lower f-numbers) create a narrow depth of field, which can help isolate a subject and is one of the greatest compositional tools at your disposal (think portraiture).

With the aperture set to f/3.5 on the left, you have a blurrier background. Also notice that the shutter speed (1/640th) is fairly HIGH, we’ll get to this later.

A little bit smaller aperture (bigger number), makes the background come into focus a bit more, and the shutter speed is slowed down.

Now, remember that all three parts work together? You probably started seeing how if you noticed the shutter speed changing with each of those different aperture values in the pictures above.

 

Shutter Speed

Shutter speed is a measure of how long the shutter remains open and thus, how long the sensor is exposed to light. Faster shutter speeds give the sensor less time to collect light and thus, result in a lower exposure. Slower shutter speeds allow more time for the sensor to collect light and result in a higher exposure.

 

In this case, the reason we might want to use a higher shutter speed is to stop motion, whether that be camera shake or a subject that is moving, allowing us to maintain sharpness. Remember, as long as the shutter is open, the camera is essentially recording the position of elements in the frame; if one of those elements moves, the result will often be undesired blurriness.

 

ISO

Back when film ruled the land, there wasn’t the kind of flexibility in this third side that we have now. You might say the exposure triangle was a two-sided polygon (the geometry of that is another discussion, but I promised this wasn’t a geometry lesson). One could control the sensitivity to light of the film they used, but once the roll was in the camera, there was no changing it. Nowadays, we can control the sensitivity of the digital sensor on the fly, though technically, we’re not controlling the sensitivity; this actually controls a post-image gain applied to the signal, but for all intents and purposes, you can think of this as sensitivity.

 

Increasing the ISO essentially allows you to work with less light. As always, though, there’s a tradeoff: increased ISOs result in increased noise and less detail. Noise is the result of random fluctuations in an electrical signal. At lower ISOs, the magnitude of the image signal is large relative to the noise (signal to noise ratio), meaning the noise generally remains unobtrusive. When working at higher ISOs, the image signal is generally close in magnitude to that of the noise and thus, noise enters the image.

 

Often, when working in lower light, you will find yourself at a point where you are using the widest possible aperture and the slowest shutter speed you can to stop action. At this point, your only choice is to increase the ISO. The lens cannot physically open itself any wider and as discussed above, sacrificing sharpness for a slower shutter speed is rarely advisable. I would rather have a grainy image that shows a well-defined subject than a smoother image with a subject lost in blur.

There was no light in this room except for the tiny music stand lights you see in the right corner.
1/80s, f/2.8 at 200mm and ISO 6400

The use of a long shutter can create very pleasing effects as well.
6s, f/16 at 17mm and ISO 100

 


Shutter Speed

The shutter speed is how fast the shutter opens and closes. If the shutter is open longer, more light is let into the camera. If it opens and closes really fast, less light is let in. If you have a wide open aperture, your shutter speed will need to be faster, because you’re already letting a lot of light in the lens opening. If your aperture is small, your shutter will need to move slower, so there is more time for light to get to the sensor.

 

If you want to freeze the action, or hand-hold your camera, then a faster shutter speed is needed. If you want to create blur, then you need a slower shutter speed. For example:

The vehicle in the photo on the left was driving past the house quite fast, but since the shutter speed set to 1/2000th of a second, it froze the action. It looks like the vehicle could be sitting still in the middle of the road. The truck on the right is a blur going past, but everything else is still. 1/10th of a second was slow enough to blur the truck as it sped past. Notice the f-stop. Since the shutter was open for so long, the opening in the lens needed to be smaller to balance the exposure.


ISO

The ISO is your camera’s mood. It can be all uptight and picky, or it can be easy-going and laid back. If you have the ISO set to a low number (100) your camera will want light, and plenty of it, because it’s going to take a smooth, crisp picture, and this requires perfect conditions. If you have your ISO set to a high number (3200) it can handle low light, because it’s not going to work as hard – a noisy (grainy) picture is good enough for Mr. High ISO.

 

So, how does this apply to your photography? Let’s say you wanted to take a picture in the evening, and you don’t want to use a flash. Just bump the ISO up, and it will allow you to have a faster shutter speed, or a smaller aperture (bigger number) and still accept the light conditions to expose correctly. Or, if you’re taking pictures at a sporting event, and you want to make sure you catch that action, but the light isn’t great, bump the ISO up. Or you may even want that moody grainy effect (it can be really cool)!

 

If you ever get frustrated because there’s just not enough light, and your pictures are blurry because the shutter speed isn’t fast enough, and you’re about to scream – just remember to bump the ISO. You could also leave this on Auto, but I usually don’t. My camera always seems to choose a higher ISO than I feel it needs. However, don’t forget to put it back down after you’re done. You don’t want to take a whole bunch of photos in the middle of the day at a 3200 ISO because you forgot to change it after your evening indoor party photos the night before.

Here’s a little demonstration:

ISO 3200

 

The photo above was taken in a very dimly lit room. Notice the digital noise?Notice the crispness of the photo below?

ISO 100

In traditional (film) photography ISO (or ASA) was the indication of how sensitive a film was to light. It was measured in numbers (you’ve probably seen them on films – 100, 200, 400, 800 etc). The lower the number the lower the sensitivity of the film and the finer the grain in the shots you’re taking.

 

In Digital Photography ISO measures the sensitivity of the image sensor. The same principles apply as in film photography – the lower the number the less sensitive your camera is to light and the finer the grain.

 

Higher ISO settings are generally used in darker situations to get faster shutter speeds. For example an indoor sports event when you want to freeze the action in lower light. However the higher the ISO you choose the noisier shots you will get. I’ll illustrate this below with two enlargements of shots that I just took – the one on the left is taken at 100 ISO and the one of the right at 3200 ISO

100 ISO is generally accepted as ‘normal’ and will give you lovely crisp shots (little noise/grain).

 

Most people tend to keep their digital cameras in ‘Auto Mode’ where the camera selects the appropriate ISO setting depending upon the conditions you’re shooting in (it will try to keep it as low as possible) but most cameras also give you the opportunity to select your own ISO also.

 

When you do override your camera and choose a specific ISO you’ll notice that it impacts the aperture and shutter speed needed for a well exposed shot. For example – if you bumped your ISO up from 100 to 400 you’ll notice that you can shoot at higher shutter speeds and/or smaller apertures.

 

Situations where you might need to push ISO to higher settings include:

 

  • Indoor Sports Events – where your subject is moving fast yet you may have limited light available.
  • Concerts – also low in light and often ‘no-flash’ zones
  • Art Galleries, Churches etc- many galleries have rules against using a flash and of course being indoors are not well lit.
  • Birthday Parties – blowing out the candles in a dark room can give you a nice moody shot which would be ruined by a bright flash. Increasing the ISO can help capture the scene.

Mirror lens

500mm f8 Mirror lenses from Nikon, Zeiss and Tamron

 

A mirror lens, also known as reflex or catadioptric lens, was once very popular, but now it has been largely forgotten. It can see far and is small and light. Mirror lenses are telephoto lenses that use a combination of two mirrors to reflect light back and forth between the ends of the lens prior to the light passing through to the camera.  This means that the physical size of the lens is around a third of the size of a conventional lens and the mirrors are also much lighter than the optical glass.

Diagram showing light path through a mirror lens (Camera on right)

 

The small physical size and weight of the Mirror lens means that it is possible to hand hold with an appropriately fast shutter speed and of course the lens does not look like a paparazzi tool, so it is discrete. It is also far more likely that you’ll be carrying a mirror lens, it is unlikely that you’ll pack a 500mm F4 refractive lens for a walk about town! Mirrors are significantly cheaper than conventional long telephotos,

 

Mirror lenses have no mechanical or electronic link with the camera body as there is no variable iris, so it is possible to fit almost any mirror to almost any SLR with an appropriate adapter.


Print Production will be in a separate Document


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