basic law of radiometry and photometry
general principle that, in the absence of losses, the elementary radiant flux or luminous flux, d
Note 1 to entry: The basic law of radiometry and photometry is expressed by
where the proportionality factor for this geometrical condition is equal to the radiance or luminance, respectively, within the elementary beam.
Note 2 to entry: The basic law of radiometry and photometry is based on the geometric extent.
Note 3 to entry: This entry was numbered 17-78 in CIE S 017:2011.