Abstract

It is well known that luminance of colored light is not always equal to that of a given reference light in the heterochromatic brightness matching. A number of studies have shown this brightness-luminance discrepancy with various experimental conditions, however, only a few studies have measured the amount of the discrepancy, using a field size of about 2 degrees, for a large number of test stimuli sampled systematically in a wide region of the chromaticity diagram [1-3]. Therefore, in the present study, we used 195 test stimuli distributed uniformly in the whole area of the CIE 1976 (u',v') chromaticity diagram. We measured the luminances (L) of these lights that appeared equally bright as the achromatic reference light with a fixed luminance (B), and determined the brightness-to- luminance ratios, the B/L ratios, for the stimuli. Simultaneously, we measured perceived saturation and hue of the test stimuli to investigate how the B/L ratio is related to the saturation and hue.

© 1992 Optical Society of America