NOTE: This term’s definition was changed in RP-16-17 Addendum 1. Deletions have a strike-through. New text is bold.
A luminous efficiency function that closely represents the average color-normal observer based on the Vos modification of Judd’s modification to the V(λ) function. VM(λ) is a supplement to, and not a replacement of, the V(λ) function and differs from V(λ) only at wavelengths below 460 nm* (see Table 13.9). This function principally is of interest in the visual sciences.
* CIE No. 86, CIE 1988 2o Spectral Luminous Efficiency Function for Photoptic Vision. Vienna, Austria: International Commission on Illumination; 1990.« Back to Definitions Index