diffusion factor, <of a diffusing surface, by reflection or by transmission>
quotient of the mean of the values of luminance,
Note 1 to entry: The diffusion factor is intended to give an indication of the spatial distribution of the diffused flux. It is equal to 1 for every isotropic diffuser, whatever the value of the diffuse reflectance or diffuse transmittance.
Note 2 to entry: This way of defining the diffusion factor can be applied only to materials for which the scattering indicatrix does not differ appreciably from that of ordinary opal glasses.
Note 3 to entry: For indicating the shape of the scattering indicatrix it is recommended that the diffusion factor,
Note 4 to entry: The diffusion factor has unit one.
Note 5 to entry: This entry was numbered 845-04-89 in IEC 60050-845:1987.
Note 6 to entry: This entry was numbered 17-312 in CIE S 017:2011.