Contribution to the experimental review of the colorimetric standard observer

The color-matching functions of six observers have been measured in the ran ge of 400-700 nm in intervals of 10 nm using two modified Donaldson-type co lorimeters at a luminance of 4.5 cd/m(2). A statistical study has been carr ied out to determine the interobserver variability (in our results), and th e results of other authors using various representational color systems hav e been compared with ours. The most important findings are that, although a common mathematical mean cannot be found, the shape of the curves for the color-matching functions obtained in our laboratory for all the observers i s very close to that of other authors, thereby implying that the overall co lor response of the human visual system is similar in all observers. In add ition, the results show that, for the long wavelengths (around 600 nm), a g reat amount of desaturant primary (460 nm) is necessary, indicating possibl e rod intrusion under our experimental conditions. (C) 1999 John Wiley & So ns.