All silver halides used in traditional black and white emulsions are sensitive to blue light, but early photographic materials had only this sensitivity. Blur is unsharp image areas, created or caused by subject or camera movement, or by selective or inaccurate focusing. Boom is an adjustable metal arm, attached to a firm stand, on which lighting can be mounted. Some booms are also made to support cameras. Borax is a mild alkali used in fine grain developing solutions to speed up the action of the solution.
Border is the edge of a photographic print - either left white, or printed black.
Boric acid is a compound used in certain fixers to prolong shier hardening life. Bounce light is a light that is directed away from the subject toward a reflective surface. Box camera is the simplest type of camera manufactured, and first introduced by George Eastman in 1888. It consists of a simple, single element lens, a light tight box and a place for film in the back. Bracketing is the technique of shooting a number of pictures of the same subject and viewpoint at different levels of exposure.