ILLUMINANCE
Definition
An <ILLUMINANCE> is a <Property> that is the total luminous flux incident on a surface, per unit area. It is a measure of how much the incident light illuminates the surface, wavelength-weighted by the luminosity function to correlate with human brightness perception. It is calculated as E_v=dPhi/dA where dPhi is An <LUMINOUS FLUX> incident on an element of the surface with <AREA> dA