The Dependence of Color upon Area

Abstract

Artists and painters have known for some time that colors change in appearance as they are made larger. More recently it has been observed that colors in enlarged photographic color prints sometimes appear to be different from those in smaller originals despite rigorous control of chemical and physical factors involved. The present investigation represents an attempt to measure differences in the appearance of certain colored surfaces as they occupy greater and greater portions of a visual field of uniform brightness. Reports of related sensory phenomena go back in the technical literature at least to Maxwell who reported, in 1856, that the color of a blue visual field was different when viewed by a small macular area than when it was viewed by larger more peripheral areas.1 Charpentier reported in 1886 that green became brighter as the viewing field was enlarged.2 In 1893, Hering found, by enlarging the visual angle of a centrally fixated field, that a mixture of red and green spectral stimuli became greener than a homogeneous spectral yellow which had been visually matched by the mixture at the smaller angle.' Kinig in 1894 observed the related fact of macular tritanopic dichromasy.4 Somewhat later a number of investigations began to appear in the literature reporting various changes in color vision as retinal fields were varied in visual angle from as little as 12 to as much as 250.5 In these studies the surround was either