6533b822fe1ef96bd127d5f6

RESEARCH PRODUCT

Absence of lightness constancy as a deficit of monochromatic vision

H. A. TauschC. Von Campenhausen

subject

LightnessSpectral sensitivityOpticsColoredbusiness.industryDaylightRadiometric dataStandard illuminantScotopic visionMonochromatic colorbusinessMathematics

description

Dark-adapted human subjects arranged a collection of colored papers in a sequence according to their lightness. The sequence of the papers (which appeared gray to the subjects) varied under different illuminant spectra. These variations could be predicted quantitatively from the radiometric data and human scotopic spectral sensitivity. By substitution of natural daylight spectra in the computation it was shown that monochromats cannot perceive lightness reliably under the changing illuminant spectra of our planet. Animals need some degree of lightness constancy to detect figures against a background reliably. This can be achieved only with the help of additional light receptors of different spectral sensitivity.

https://doi.org/10.1007/978-94-011-0507-1_23