Nikon® D3000: Digital Field Guide

GLOSSARY

Active D-Lighting

A camera setting that preserves highlight and shadow details in a high-contrast scene with a wide dynamic range.

AE (Autoexposure)

A function of a camera where the camera selects the aperture and/or shutter speed according to the camera's built-in light meter. See also Aperture Priority, Shutter Priority, and Programmed Auto.

AE/AF (Autoexposure/Autofocus) Lock

A camera control that lets you lock the current metered exposure and/or autofocus setting prior to taking a photo. This allows you to meter an off-center subject and then recompose the shot while retaining the proper exposure for the subject. The function of this button can be altered in the setup menu.

AF-assist illuminator

An LED light that's emitted in low-light or low-contrast situations. The AF-assist illuminator provides enough light for the camera's AF to work in low light.

ambient lighting

Lighting that naturally exists in a scene.

angle of view

The area of a scene that a lens can capture, which is determined by the focal length of the lens. Lenses with a shorter focal length have a wider angle of view than lenses with a longer focal length.

aperture

The opening of the lens similar to the iris of an eye. The designation for each step in the aperture is called the f-stop. The smaller the f-stop (or f-number), the larger the actual opening of the aperture; and the higher-numbered f-stops designate smaller apertures, letting in less light. The f-number is the ratio of the focal length to the aperture diameter. ...