AE Automatic Exposure metering, i.e. the camera measures the light and sets shutter speed and aperture (either or both).
AE lock (AE-L) Locks an automatic exposure setting in the camera's memory.
AF lock (AF-L) Locks an auto-focus lens at its present focus distance.
Aliasing The jaggy edges that appear in bitmap images with curves or lines at any angle other than multiples of 90°.
Angle of view The extent of the view taken in by the lens. It varies with focal length for any particular format size. The angle made at the lens across the image diagonal.
Aperture (of lens) Size of the lens opening through which light passes. The relative aperture is calibrated in f-numbers, being the diameter of the beam of light allowed ...