COLORIMETRIC IMPLICATIONS OF THE STANDARD OBSERVER (2-DEGREES) IN METAMERIC MATCHES

Many works have shown colorimetric additivity failures in colour-match ing experiments. Thus, in the present work, using the colour-matching functions (CMF) of three real observers, we have conducted five experi ments in isomeric and metameric matching. The stimuli matched, using t wo modified Donaldson colorimeters, were two achromatic, one blue, one orange and one green. Afterwards, we determined both the isomeric and the metameric discrimination ellipsoids for all the matches and for e ach observer. The results reflected differences in chromaticity and lu minance with respect to the results of the CIE-1931 Standard Observer. When we compared our results (of each observer with his CMF) for the isomeric and metameric matches, we found that, according to the differ ential colour thresholds, the prediction was acceptable for chromatici ty but not for luminance. The experimental results revealed the need t o revise some aspects of the CIE-1931 Standard Observer.