Brightness

A basic visual sensation describing the amount of light that appears to emanate from an object, or more precisely, the luminance of an object

The amount of power that can be delivered per unit solid angle by a directed energy weapon. As used in the BMD program, brightness is the measure of source intensity. To determine the amount of energy per unit area on a target, both source brightness and source-target separation distance must be specified.

An attribute of visual perception in which a source appears to emit a given amount of light. Note 1: "Brightness" should be used only for nonquantitative references to physiological sensations and perceptions of light. Note 2: "Brightness" was formerly used as a synonym for the photometric term "luminance" and (incorrectly) for the radiometric term "radiance."