Like Skiing Like Photography

Somewhere and sometime in the distant past I recall reading a skier talking about how he thought the improvement in ski technology would make better skiers of many people. He confessed that he was wrong on that count.

Same too with photography. I find it hard to believe that with modern cameras people do not take better pictures. What it comes down more often then not is exposure exposure exposure. Exposure is a fundamental technical matter you have to master in order to take respectable photographs.

What is Exposure?

Exposure is control over the amount of light that falls onto the pixels. Digital cameras provide three ways to control the exposure (film cameras could meaningfully give you two ways to control the exposure): the ASA, the aperture, and the shutter speed.


ASA is what was once commonly referred to as film speed. The higher the ASA the more sensitive the pixel are too light. In the old film days ASA was chosen by the film you used (common ASAs were 100, 400, and 1600) and set for that roll of film (though you could set the camera to anything you wanted and adjust in the darkroom) and that was it. Today’s digital cameras allow you to set the ASA for each picture you take.

The cost is roughly the same. In the old days, higher ASAs meant grainer photographs and in the digital world higher ASAs mean more noise in the photogrpah.


Digital cameras like film cameras often allow you change the size of the lens opening to allow more or less light in. Make that opening larger (smaller F-Stop number) and more light comes in. The cost likewise is the same, the larger the opening (the smaller the F-Stop number) the more accurate your focusing must be. Conversely, the larger the F-Stop number (smaller aperture) more of the photograph will come into focus. Those of you who need reading glasses can see this in your own eyes in the fact it is easier to read the same type in bright light.

Shutter Speed

The other factor in setting your exposure is the shutter speed. The shutter speed is simply the amount of time the camera allows the light to fall upon the pixels. Obviously, slower shutter speeds mean more light falls onto the pixels.

The cost? Typically slower shutter speeds means you need to brace your camera or shoot only slow moving subjects. Usually, photographers see faster shutter speeds as a cost-free transaction, but they will require more accurate focusing as they typically mean larger apertures. Often times too slow shutter speeds can be used to add the sense of action or motion to the subject (blurring).

Examples and Exercises

Unfortunately, I do not have a set of example photos showing you the results of each exposure control factor, but that is coming!

Good Stuff!

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