Bathing grizzly bear @ f/5.6
What Is Aperture?
An aperture is simply defined as an opening, hole or gap. In photographic terms, we use it to describe the hole in the middle of the lens that allows light to pass from the front of the lens, through the lens barrel and onto the camera’s sensor. Varying the size of this aperture has a dramatic effect on the look of your photo and along with shutter speed and ISO, it’s also part of our exposure triangle. Not only does the aperture affect the brightness of our photos, but it also controls how blurry our background is.
Aperture Size – F-Stop
Aperture settings are referred to as f-numbers and individual settings are f-stops (eg. f/8). The larger the f-number, the smaller the aperture is. For example, an f-stop of f/32 would be considered a very small aperture, whereas an f-stop of f/1.4 would be considered a very large aperture (see diagram below). Different lenses have different maximum and minimum f-stops. Most of the time, people do not care what the minimum aperture of a lens is, but they almost always care what the maximum aperture is. We’ll get into the reason for this as we progress through the article.
Just like the retina of a human eye, the aperture of a lens is controlling how much light passes through it.
When talking about camera settings, it’s common for people to use both aperture and f-stop. For example, you might hear someone ask: “What f-stop are you using?” or “What is your aperture setting?” Both of these mean exactly the same thing and both of those questions would be answered with an f-number. eg. “f/2.8”