The appreciation of LED

The aim of this study was to evaluate differences in appreciation for LED-based white-light sources between Dutch and Chinese people, when used for the illumination of three applications: fresh food, packaging material and skin tone. Furthermore, the contribution of the CIE special and general colour rendering indices (Ri and Ra), a colour gamut measure (Ga), and chroma changes for specific test-colour samples to perceived attractiveness was investigated. Thirty-four Dutch and 36 Chinese people assessed the attractiveness of the object appearance, with paired comparison experiments, for seven light sources at two CCT settings, 3000 K (Dutch and Chinese) and 4000 K (Chinese only), and a range of Ra and Ga values. It was found that for illuminating fresh food and packaging material, most Dutch and Chinese participants preferred light settings with an increased colour gamut. In contrast to colour rendering indices, the chroma change for the strong red test colour sample could be used to predict object attractiveness, but the established equations were different per application and culture. There was no clear relation between objective measures and skin tone preference for the Dutch study. Finally, Chinese participants did not like an increase in red saturation at 3000 K, but they allowed an increase at 4000 K