Digital Travel Photography Digital Field Guide

Glossary

ambient lighting

Diffuse non-directional lighting that doesn't appear to come from a specific source, but rather bounces off walls, ceilings, and other objects in the scene when a picture is taken.

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.

anti-alias

A process that smoothes the look of rough edges in images (called jaggies or staircasing) by adding partially transparent pixels along the boundaries of diagonal lines that are merged into a smoother line by our eyes. See also jaggies.

aperture-preferred

A camera setting that allows you to specify the lens opening or f-stop that you want to use, with the camera selecting the required shutter speed automatically based on its light-meter reading. See also shutter-preferred.

autofocus

A camera setting that allows a camera to choose the correct focus distance for you, usually based on the contrast of an image (the image will be at maximum contrast when in sharp focus) or a mechanism such as an infrared sensor that measures the actual distance to the subject. Cameras can be set for single autofocus (the lens is not focused until the shutter release is partially depressed) or continuous autofocus (the lens refocuses constantly as you frame and reframe the image).

autofocus assist lamp

A light source built into a digital camera that provides extra illumination that the autofocus system ...