Nikon® Creative Lighting System Digital Field Guide, Third Edition

Glossary

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

AF-assist Illuminator An LED that emits light in low-light or low-contrast situations. The AF-assist Illuminator provides enough light for the camera’s autofocus 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. The angle of view of a specific focal length changes depending on the image format (such as DX or FX). See also DX and FX.

aperture The physical 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 is, the larger the actual opening of the aperture. 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.

Aperture Priority mode A camera setting in which you choose the aperture and the camera automatically adjusts the shutter speed according to its metered readings. Aperture Priority controls the depth of field. See also Auto exposure mode and Shutter Priority mode.

aspect ratio The proportions of an image as printed, displayed on a monitor, or captured by a digital camera.

Auto exposure mode (AE) A general-purpose ...