Technical Details of Photography Part 2

Hi everyone! Previously, I talked about how to use the histogram, which is an aspect of the technical details of photography. In this blog post, I will wrap up the technical talk by explaining suitable aperture, shutter speed and ISO settings for nature photography, which can be difficult to grasp with all the numbers.

I can speak for myself when I say that fractions and decimals make everything difficult when they come into play in and outside of math, but sadly, they appear in photography for aperture. Rob Sheppard's definition of aperture in The Magic of Digital Nature Photography is "a variable opening inside the lens that controls the amount of light coming through" (Sheppard, 52). Aperture is measured in f/stops, in which the numbers are fractions. If you understand the concept that larger denominators make the fractions smaller and small denominators make the fractions bigger, then aperture and shutter speed will be easier to grasp. In aperture, large numbers like f/16, are small apertures while small numbers like f/5.6 or f/2.8 are large apertures. Small apertures have a smaller amount of light coming in the lens, while large apertures have more light entering the lens. Aperture also affects the depth of field. According to Sheppard, "depth of field increases as you choose f/stops toward the f/22 end, and it decreases as you move toward f/2" (Sheppard, 52).

Fractions also have to make shutter speed more difficult to understand at first as well. Shutter speed influences the light coming into the lens, like aperture does, but in a different way. According to Sheppard, "shutter speed affects how long the light is allowed to come through the camera and strike the sensor" (Sheppard, 53). Shutter speed is measured in seconds and is also a fraction but can be seen as a single number, like 125. 1/125 second is twice as much as 1/250 second, so 1/125 second lets in light twice as much. Faster shutter speeds, like 1/250, will stop action in a scene but slower shutter speeds will blur a moving subject. When taking photographs without a tripod and/or having fast moving subjects, it's best to have a faster shutter speed so that the movement of your arms isn't seen as blurs in the photograph. Depending on the program/mode your camera is on, your shutter speeds may need to differ. In addition, there are different minimum shutter speeds depending on what kind of lens you are using on your camera. In the case of my camera, in which the lens is under the four thirds category and is a wide-angle lens and is 18mm and wider, my minimum would be 1/30 second. If you would like to set your own shutter speed and aperture, it's best to use the Manual Exposure setting on your camera to take better pictures in accordance to the setting.

Rob Sheppard's definition of ISO is "an international standard for film from the International Organization of Standards (ISO was chosen as a simple letter designation for certain standards, like the speed of film, it is technically not an acronym)" (Sheppard, 56). Different ISO settings have their own sensitivity to light. For example, a low ISO setting, like 100, is less sensitive to light than 400. ISO values of 100 or less give the best results with better sharpness, color, tonality, and low grain/noise, but it also means a slower shutter speed. Nature photographers with APS-C or Four Thirds cameras will use ISO 100 or less for better results, while DSLR's will use ISO settings up to 400.

In the first photograph, I my camera set to the ISO setting of 400, a shutter speed of 1/320 (because I was carrying my camera), and an aperture of f/5.6. Because of the higher ISO setting, my camera was more sensitive to the light coming into the lens, which made the photograph over exposed and the colors are really washed out. In the second photograph, I changed the ISO setting to 100, which made a big difference in how the light affected the exposure and color in the photograph. We can see that the light entry is more controlled, which helped see the colors better in the photograph and it's not so overexposed. In both photographs, the small aperture affected the depth of field, so we only see a thin line in the background of what was farther away, rather than an outline of some sort.

To wrap all of this up, what aperture, shutter speed, and/or ISO setting has been the most helpful to you for nature photography? Which have you found more difficult?

Bibliography: Sheppard, Rob. The Magic of Digital Nature Photography. New York: Lark, 2007. Print.

Technical Details of Photography Part 1

Hi everyone! When we think about photography, we always think about what's in the photograph and the artistic side of photography, but we never think about the technical details of photography; with the features on the camera we're using, aperture, shutter speed, etc. In this blog post, we will talk a bit about how to evaluate a photograph's exposure through the histogram.

According to The Magic of Digital Nature Photography by Robert Sheppard, the histogram is a "graph of the tonalities that your sensor records from the scene" (Sheppard, 51). It is a better interpretation of the exposure of your photographs than the LCD monitor. The left side of the histogram represents the shadows and the amount of black in the scene, while the right side represents the highlights and the amount of white in the scene.

There are certain details you can look out for when you are looking as to whether your photograph is properly exposed or not. When there is a gap or cliff at the right side of the histogram, then the exposure isn't completely optimal. When you look for a gap or a cliff enough times, then it becomes instinctive, and allows you to use the histogram to look out for certain things:

1.) Clipping - "if a histogram hill stops at a steep cliff at the right side, detail is clipped. This means there are additional tones and colors that could be captured, but are not because the detail is 'clipped' off" (Sheppard, 52). When this happens, you have reached your sensor's capacities and highlights are blown out.

2.) Gaps - you want to avoid gaps on the right side of the photograph because it shows that you have gaps in the tonal details of the photograph.

3.) Tonalities - It's important to watch where main tonalities fall because you don't want all of the tonalities in dark subjects to fall on the left side of the histogram. It would give less "noise" and better color if you add exposure to the photograph. You can increase exposure by adjusting aperture and shutter speed, which I will talk about in a different blog post.

Now, here are some examples of proper and improper exposure:

This picture was taken when doing a fall photo shoot with my friend, Carissa. When evaluating the histogram for the photograph, I saw that the photograph was underexposed, because the bulk of the graph is more towards the left side and the hill on the right side doesn't gradually decrease. If it would have proper exposure, then the hill would be towards the center and the cliff on the right side wouldn't be there. When we look back at the photograph, we can see that the leaves of the tree are dark, which can give a hint that there could be an exposure problem.

An example of proper exposure is the photograph of my friend, Carissa, swinging with trees in the background. When looking at the histogram, the hill is in the center, which tells us that the light is more evenly distributed, rather than the light or darkness going towards one side of the photograph. When we look back to the photograph, we can see that there aren't any areas where it is too dark, but there aren't any parts where the sun is blinding anything.

To wrap this up, have you ever used the histogram before? What are some tips that you have to create proper exposure for a good histogram?

Works Cited: Sheppard, Rob. The Magic of Digital Nature Photography. New York: Lark, 2007. Print.