VISUAL EVALUATION OF CIE 2015 CONE FUNDAMENTAL-BASED 10° COLOUR MATCHING FUNCTIONS FOR LIGHTING APPLICATIONS

Abstract

The CIE 2015 cone fundamental-based colour-matching functions (CMFs), especially the 10° CMFs, are expected to improve visual colour matching in lighting applications. The chromaticity specifications for lighting products are based on the CIE 1931 CMFs (2° observer) and are given by correlated colour temperature (CCT) and the distance from Planckian locus (Duv). To study the impact of introducing the CIE 2015 CMFs, computational analyses were first made to determine the magnitude of changes in CCT and Duv values for various lighting sources. The results showed significant changes in both CCT and Duv. Then vision experiments were conducted to compare the CIE 2015 CMFs and the CIE 1931 CMFs for visual colour matching of lights with various spectral distributions. The results showed that CIE 2015 10° CMFs performed better overall but also that there is a strong dependence on the age of subjects and the spectral distribution of light sources.