ABSTRACT
As we learned in Chapter 4, the aperture of the camera controls the amount of light that enters the camera through the lens and passes along to the image-capture device. The aperture setting is referred to as the f-stop. The “f” stands for focal, and is sometimes also expressed as the focal ratio of the lens. As we also learned, this number is the ratio of the diameter of the opening to the focal length of the lens. The f-stop is not an absolute number, in that it doesn’t measure a specific quantity of light, but instead measures a relative amount of light compared to the other f-stop settings. Typical lenses might have the following options available:
f/1.4 – wide open
f/2
f/2.8
f/4
f/5.6 – middle of the road
f/8
f/11
f/16
f/22 – very tightly closed down
