COLORIMETER CALIBRATION

A colorimeter with multiple sensings of light to provide higher accuracy measurements of the primaries of a human-standard observer based color space is provided. This color space (target color space) must have the characteristic of two chromaticity coordinates and an achromatic primary like CIELAB, CIELUV or xyY in CIE 1931. The calibration of the device includes training with a set of calibration illuminants. Two sets of calibration-factors are determined. The first set of calibration factors yields intensity of primaries optimized with respect to chromaticity, the second set yields the optimized intensity of the achromatic primary. The combination of these sets of calibration factors enable the colorimeter to deliver values of that light with respect to three primaries of a human-standard-observer-based color space optimized with respect to chromaticity and the achromatic primary.