SIMULTANEOUS COLOR CONTRAST WITH A LARGE SURROUNDING FIELD

Abstract

The simultaneous color contrast was investigated for two different stimulus conditions. One was to use a semi-circular surrounding field so that the visual angle of the surround can become very large, larger than 180 degrees. The other was to use a flat colored paper of an extremely large size. The color appearance of the central gray test patch was measured by the elementary color naming method at different viewing distance. The vividness of the test patch color increased for larger visual angle of the surround but the way of the increase differed between the two conditions. The relationship between the test patch color appearance and the surrounding color appearance was same as the result obtained by the two rooms technique an by the afterimage experiment to indicate the simultaneous color contrast takes place by the same mechanism of the visual system, that the SCC phenomenon also occurs because of the brain chromatic adaptation to illumination.