Nikon® D5000 Digital Field Guide

Glossary

Active D-Lighting

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

AE (Auto-Exposure)

A general-purpose shooting mode where the camera selects the aperture and/or shutter speed according to the camera's built-in light meter. See also Shutter Priority and Aperture Priority.

AE/AF (Auto-Exposure/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 Custom Settings menu (CSM f7).

AF-assist illuminator

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

AF-S

See Single Autofocus.

ambient lighting

Lighting that naturally exists in a scene.

angle of view

The area of a scene that a lens can capture, 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 lens opening through which light passes. 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; the higher-numbered f-stops designate smaller apertures, which let in less light. The f/number is the ratio of the focal length ...