Effect of correlated colour temperature on the perception of interiors and colour discrimination performance.

摘要

My choice of a favourite Boyce paper has as much to do with association as with content. It concerns a topic that is, for me, an intriguing conundrum of lighting research dating back 77 years. It was in 1941 that an article by AA Kruithof in the Philips Technical Review introduced Europe to the fluorescent lamp, which had appeared three years earlier in the USA. This novel lamp offered a source of white light with a choice of colour temperatures, but users were cautioned to exercise care when selecting CCT. A chart relating CCT to illuminance was accompanied with a caption advising that, "For every colour temperature there exists a highest and a lowest level of illumination at which the illumination is considered "pleasing": at lower levels the illumination appears dim and cold, and at higher levels the colour rendering is unnatural."1 The 'pleasing' zone of the chart corresponds to in-step combinations of E and CCT for which both variables are either high, intermediate or low, and this preferred interaction has become known as the Kruithof factor. The chart has been reproduced many times and is widely acknowledged by lighting designers, despite a lack of validation from several research studies that have sought to reproduce Kruithof's findings.