PSYCHOPHYSICAL INVARIANTS OF ACHROMATIC COLOUR VISION .2. ALBEDO/ILLUMINATION SUBSTITUTION

Lie, I. Psychophysical invariants of achromatic colour vision. II. Albedo/ illumination substitution. Scand. J. Psychol., 1969,10, 176–184.—Can ‘identification of illumination’ be identified as one of the determinants of achromatic vision? Colour constancy is redefined in terms of deviation from albedo/ illumination substitution (A/I‐substitution). A series of A/I‐substitution experiments, performed under conditions assumed to provide minimal possibilities for identification of illumination, indicate that complete A/I‐substitution (zero constancy) is obtained for both brightness and whiteness, provided the test fields are equated with respect to colour temperature and perceived texture. Copyright © 1969, Wiley Blackwell. All rights reserved