An Examination of use of Alternative Reference Sources in Colour Rendering of Environmental Lighting Applications

Environmental lighting applications include smart technologies with energy efficiency, zero toxic elements production, decreased number of luminaires, longer life span, etc. While the research is focused on energy performance and lighting requirements there must be attention for the users’ wellbeing even if the energy consumption is raised. One important aspect for the wellbeing is colour rendering, which is defined as the “effect of an illuminant on the colour appearance of objects by conscious or subconscious comparison with their colour appearance under a reference illuminant”. Reference is the foundation of communication, but no possible reference is inherently superior. The use of Planckian radiation, daylight, or a combination of the two has been established as a reference source because people are familiar with those two non-artificial light sources. Special lighting applications, like tunable light, are based on special specifications and the establishment of alternative design reference sources according to these specifications is a possibility for a better colour rendition. In the present study, different sources were designed with hue-specific chroma changes, and the results of colour rendition were compared with the relative results of standard reference sources. The exported results are reported, and proposals are made for the use of the results.