Active D-Lighting A camera setting that preserves highlight and shadow details in a high-contrast scene that has a wide dynamic range.
AE (Auto-Exposure) 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 (Auto-Exposure/Autofocus) Lock A camera control you use to 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 is selected in the Setup menu under the Buttons heading.
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; the higher-numbered f-stops designate smaller apertures, letting in less light. The f-number is the ...