Difference between revisions of "Diffusion Factor"

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Diffusion Factor (of a diffusing surface, by reflection or by transmission)

The ratio of the mean of the values of luminance measured at 20 and 70 degrees to the luminance measured at 5 degrees from the normal, when the surface considered is illuminated normally.

Symbol: s

Note 1: The diffusion factor is intended to give an indication of the spatial distribution of the diffused flux. It is equal to 1 for every uniform diffuser, whatever the value of the diffuse reflectance.

Reference: C.I.E. (extract)

Note 2: The full text of the Reference: C.I.E. definition explains the limitations within which this form of definition can be applied.

Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)

English