Aperture - Exposure Triangle Part 2
Exposure triangle include Shutter speed, Aperture and ISO. In first part we have discussed Shutter Speed. If you have not read the first part. Read here.
Simply speaking, Aperture is the physically adjustable opening in the lens which determines how much light is entering the camera. Aperture is placed in front of the shutter and you can manually adjust aperture with a button or dial in the camera. If you are shooting in Auto Mode, the camera will determine the appropriate aperture and determines the amount of opening.
Aperture is denoted by F-stops, - f/1.4, f/4, f/6.3 etc.. Higher the f-stop, narrower the aperture will be and smaller the number, wider the aperture, for example, f/1.4 have wider opening and it allows more light to enter the camera, f/22 is narrower and it allows very little light to enter the camera. When a photographer says to open the aperture, it means to reduce the actual f-number value, for example, from f/8 to f/4. Likewise, if a photographer says close down the aperture, it means to increase the actual f-number value, for example, from f/8 to f/16. It is slightly confusing at the beginning, but once you get used to it, you will not even think about it, it will become a second nature to you.
In addition to controlling how much light it enters, aperture also does another important thing, that is controlling the depth of field, which won't be discussed here because it requires its own dedicated article. (You can read it here) But, for now, just understand that lower the aperture number lower the depth of field and higher the aperture number, higher the depth of field.
Even though the main function of the aperture is to control the amount of light entering the camera and determining the depth of field, it also affects two other things which mostly side effects that the camera manufacturers never intended to make it work that way, but nevertheless, it works that way. That is optical aberrations and vignetting. Optical aberration is when a picture looks distorted or doesn’t represent the size of object s