Turn to this glossary for a quick refresher on that elusive digital photography term that's stuck somewhere in the dark recesses of your brain and refuses to come out and play. For more information about a topic, check the book's index.
24-bit image: An image containing approximately 16.7 million colors.
Adobe RGB: One of two color space options available on your camera; determines the spectrum of colors that can be contained in the image. Adobe RGB includes more colors than the default option, sRGB, but also involves complications that make it a better choice for advanced photographers than for beginners.
AEB: Auto Exposure Bracketing, a feature that automatically records multiple exposures using different exposure settings.
AE lock: A way to prevent the camera's autoexposure (AE) system from changing the current exposure settings if you reframe the picture or if the lighting changes before the image is recorded.
aperture: One of three critical exposure controls; an opening in an adjustable diaphragm in the camera lens. The size of the opening is measured in f-stops (f/2.8, f/8, and so on), with a smaller number resulting in a larger aperture opening. Aperture also affects depth of field (the distance over which focus remains acceptably sharp).
aperture-priority autoexposure: A semiautomatic exposure mode, represented by the A on the Mode dial. The photographer sets the aperture, and the camera selects the appropriate shutter speed, ...