Canon® EOS 40D Digital Field Guide

Glossary

ADEP

(Automatic Depth of Field AE) The camera mode that automatically calculates sufficient depth of field for near and far subjects within the coverage of the seven AF focusing points, such as when several people are sitting at various distances from the camera.

AE

Automatic exposure.

AE lock

Automatic exposure lock. A camera control that lets the photographer lock the exposure from a meter reading. After the exposure is locked, the photographer can then recompose the image.

AF lock

Autofocus lock. A camera control that locks the focus on a subject and allows the photographer to recompose the image without the focus changing. Usually activated by pressing the Shutter button halfway down.

ambient light

The natural or artificial light within a scene. Also called available light.

angle of view

The amount or area seen by a lens or viewfinder, measured in degrees. Shorter or wide-angle lenses and zoom settings have a greater angle of view. Longer or telephoto lenses and zoom settings have a narrower angle of view.

aperture

The lens opening through which light passes. Aperture size is adjusted by opening or closing the diaphragm. Aperture is expressed in f-numbers such as f/8, f/5.6, and so on.

aperture priority

(Av Aperture-Priority AE) A semiautomatic camera mode in which the photographer sets the aperture (f-stop), and the camera automatically sets the shutter speed for correct exposure.

artifact

An unintentional or unwanted element in an image caused by an imaging device or as a byproduct ...