Barn doors are an accessory used on spotlights and flood lamps to control the direction of light and width of the beam. Bispheric lens is a lens having different curvatures at the center and the edge, each of which forms part of a sphere. The different edge curvature brings the peripheral rays more closely to the same point of focus as the center rays. Bleaching is a stage in most toning, reducing and color processing systems. 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. Bracketing is the technique of shooting a number of pictures of the same subject and viewpoint at different levels of exposure. Brightness range is a subjective term describing the difference in illumination between the darkest and lightest areas of the subject. Brilliance is the intensity of light reflected from a surface. It is sometimes an alternative term for luminosity .