Luminance-Brightness Discrepancy in Near White Lights

摘要

The present study introduces interesting disagreement phenomena between luminance and brightness in near white colors reproduced using LEDs. Target stimuli having identical luminance and chrominance (CCT) appeared to have different brightness. Observers tended to choose brighter one from the two target stimuli in contrary fashion. The relative quantities of the ipRGC (intrinsically photosensitive retinal ganglion cells), S-cones, and rods were compared over the stimuli besides the luminance, i.e., photometric quantity. An apparent reason for the discrepancy could not be revealed in this study; however it could be induced that the contribution of S-cone, rod, and ipRGC (circadian) photosensitive receptors as well as L- and M-cones to the brightness perception causes the discrepancy results.