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Colorimetric evaluation of daylight simulator sources
Author(s) -
Hisdal Bjarne
Publication year - 1995
Publication title -
color research and application
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.393
H-Index - 62
eISSN - 1520-6378
pISSN - 0361-2317
DOI - 10.1002/col.5080200306
Subject(s) - standard illuminant , color rendering index , daylight , mathematics , color temperature , statistics , artificial intelligence , computer science , optics , physics , light emitting diode
The color shift of a sample due to a change in illuminant can be expressed either in terms of the CIE General Color Rendering Index, R a , based on the average for eight color samples, or in terms of the CIE Metamerism Index MI vis , the average for five pairs (or couples) of samples. It is shown that, in an ideal case where the eight samples constitute four complementary pairs, the value of the average for eight can be predicted accurately from the average for only four of the eight samples. This is approximately also the case for a prediction based on four of the actual eight CIE samples, but in this case there is some uncertainty in the predicted R a values. For MI vis , a useful approximation in value can be obtained using only two of the five defined couples. Finally, it is shown that R a and MI vis evaluate illuminants in largely the same way.