luminous flux emitted per unit area.
noun 1. 1 (def 2a). noun 1. energy emitted or propagated in the form of light; the product of a luminous flux and its duration, measured in lumen seconds Qv
- Luminous exitance
noun 1. the ability of a surface to emit light expressed as the luminous flux per unit area at a specified point on the surface Mv
noun, Optics. 1. the rate of transmission of luminous energy: expressed in lumens. noun 1. a measure of the rate of flow of luminous energy, evaluated according to its ability to produce a visual sensation. For a monochromatic light it is the radiant flux multiplied by the spectral luminous efficiency of the light. It is […]
noun 1. luminous flux per unit of cross-sectional area.