A Psychophysical Study of White I Neutral Adaptation

Abstract

A discussion is presented of the concept white as it is used to describe properties of light, properties of objects, and properties of sensation. The concept can have both practical and theoretical significance only when the psychophysical functions relating the sensation white to the stimulus variables are known. An apparatus and method used to obtain such functions are described. Data are presented for three observers, for a neutral state of adaptation, dark surround, 11.7° test field, and a one-second stimulus duration. White threshold contours are shown which relate the approximate color temperature of the test stimulus and the luminance required to evoke a sensation of absolute white. These contours form the lower boundary of a white sensation area, in which all color temperature-luminance combinations evoke an absolute white sensation for the given observers and experimental conditions.