Luminance Luminance Luminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction. It describes the amount of light that passes through, is emitted or reflected from a particular area, and falls within a given solid angle. The SI unit for luminance is candela per square metre (cd/m). A non-SI term for the same unit is the nit. The CGS unit of luminance is the stilb, which is equal to one candela per square centimetre or 10 kcd/m. Luminance is often used to characterize emission or reflection from flat, diffuse surfaces. The luminance
Radon measure letting the "y"-axis have measure 0 and letting the point (1/"n","m"/"n") have measure 1/"n". This measure is inner regular and locally finite, but is not outer regular as any open set containing the "y"-axis has measure infinity. In particular the "y"-axis has "m"-measure 0 but "M"-measure infinity. A topological space is called a Radon space if every finite Borel measure is a Radon measure, and strongly Radon if every locally finite Borel measure is a Radon measure. Any Suslin space is strongly Radon, and moreover every Radon measure is moderated. On a locally compact Hausdorff space, Radon measures correspond to