Unique and binary hues as functions of luminance and illuminant color temperature, and relations with invariant hues.
For aperture color 3 s stimuli, the four unique hues, and at times the four (equally-balanced) binary hues, were measured for: (1) adapting white color temperatures 2850, 3400, 5500, 6500 K; and (2) luminance (L) for 5 and 6 log L ranges (about 0.01-3200 cd/m2) in 3.2:1 L steps (viewed singly) for 1 subject per white, 3 log L in 10:1 steps for 6 subjects for white 6500 K, and 1 log L for 2-11 subjects per white. The full hue cycle is graphed to the extended wavelength scale. With higher L, unique hues *b and *y shift longer, *g and *r shorter, and spectral binaries and 460 nm are invariant wavelengths, for Ls viewed singly. But for Ls viewed in successive contrast (Bezold-Brucke effect), unique hues are practically invariants. As interstimuli interval increases from 0-40 s (from successive L contrast to no-contrast), invariants shift away from uniques (which become hue-shift maxima) and coincide with spectral binaries (but not r/b, 565 c) at 495, 546, 600 nm. Successive L contrast switches spectral uniques' hue-shift off (as invariants), and spectral binaries on (as hue-shift maxima); and no-contrast switches the reverse. With higher illuminant color temperature 2850-6500 K, wavelength of 10 constant hues shortens 5-10 nm for *b, *y, g/y, y/r, but others are constant +/- 2 nm.
Pridmore
R W
RW
Central Houses Proprietary Limited, Turramurra, NSW, Australia.
D000221:Adaptation, Ocular / Q000502:physiology*; D003118:Color Perception / Q000502:physiology*; D015350:Contrast Sensitivity / Q000502:physiology; D006801:Humans; D010775:Photic Stimulation; D012684:Sensory Thresholds