Luminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction. To put it simply, luminance is the amount of light coming from a surface. Luminance is often associated with brightness which relates to the strength of sensation resulting from viewing surfaces or spaces from which light comes to the eye. The sensation is determined in part by the luminance and in part by conditions such as the state of adaptation of the eye. The SI unit for luminance is candela per square meter (cd/m2).
