Hue Shift with Intensity (Bezo d-Brücke Phenomenon) as Studied by the “Zeta-Method”

Hue shift with intensity (Bezold-Brucke phenomenon) was investigated from a new angle, by measuring the electrical. excitability of the eye after a brief exposure to monochromatic light. The time-course of electrical excitability changed when the wave-length was varied and also when the intensity of the stimulus light of one and the same wave-length was altered. By comparison of both effects it was possible to express the intensity effect in terms of wavelengths. The results were compared with those obtained by Purdy with the method of hue matching, and satisfactory agreement was found between them.