How “aperture” plays a role in exposure

In my last post I talked about setting a foundation, by first learning about the important aspects of your camera’s controls; aperture, shutter speed, and iso which are the settings that control exposure. “Exposure” is simply the brightness of the photo captured. However, we need to learn about these three controls individually before we can completely understand exposure.

Your camera records light. “Aperture” is simply the diameter of a “hole” in the camera’s lens, that you can control , which determines the amount of light that reaches the camera’s sensor (a component in the camera that records the image).

Aperture sizes 50mm

In the diagram above, notice that “Aperture” is shown in the form of “f/n” where “n” represents the aperture setting on your camera (example; 2.8, 4, 5.6 etc…). Also notice that the lower the aperture setting, the larger the hole. This is because “f/n” represents the inverse of the aperture setting. For example if we take 50/2.8 = 17.9 we see it is a larger number than 50/4 = 12.5.

The “Aperture” setting is referred to as an f-stop meaning full stop. The diagram above shows aperture settings in full stop values. Notice the size of the hole at f/4 is half the size, or half the amount of light, of the hole at f/2.8 and f/5.6 would be half the amount of light of the hole at f/4 reaching the camera sensor etc… Also consider that the amount of light at f/4 is double the amount of light at f/5.6, because the size of the hole at f/4 is double the size of the hole at f/5.6.

For the above discussion think of the amount of light let into the camera by the aperture setting is one of the controls that has an effect on the brightness of your photo.

In the next article we will uncover the creative control behind aperture.

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