STUDIES IN METAMERISM USING DICHROIC LADDERS

Dichroic ladders, comprising a set of samples and a floater dyed with different dyes, have been used to examine metameric pairs of coloured samples. Observers were asked to select the sample from the ladder whi ch most closely matched the floater, the resulting pair being metameri c. Whilst there was a good agreement between the visually and instrume ntally selected matching ladder sample under illuminant D-65, consiste nt differences were found under illuminant A and TL84. An improvement in the level of agreement between the visual and the instrumentally de termined matching ladder sample under illuminant A and TL84 was obtain ed if tristimulus values were computed from reflectance values using w eighted ordinates interpolated to the 6 degrees and 16 degrees observe r respectively.