APPLICATION OF CIE 13.3-1995 WITH ASSOCIATED CRI-BASED COLOUR RENDITION PROPERTIES

摘要

Based on the work completed within CIE Division Reporter 1-68, the Global Lighting Association published a document and an associated calculation tool, that describes the precise procedure for computing the colour rendering indices, R_a and R_i. In addition, the document includes a colour gamut index (G_a) to indicate if the colour gamut of the test source becomes smaller or larger than the colour gamut of the reference illuminant, chroma indices (C_i) to indicate if the chroma of the test-colour samples will decrease or increase (leading to a less or more colourful appearance of object colours), and Δh_i to indicate changes in hue-angle. Together with R_a, the described properties may be useful to objectively explain why object colours can appear differently when illuminated under light sources with similar CCT and R_a values. This paper provides an overview of the CRI-based colour rendition properties and the importance of the accompanying calculation tool.