Conspicuity of chromatic light from LED spotlights

Abstract

Chromatic light in achromatic luminous surroundings has the effect of attracting attention to the area of coloured light. The strength of the effect of attracting attention and arousing visual interest depends on the intensity and spectral composition of the light. Light-Emitting Diodes excel in providing chromatic light of high saturation and are likely to produce light of higher chromatic strength than the light most users have experienced before. An experiment was performed to quantify the luminance for red, orange, yellow, green, cyan, blue and purple hues that give rise to levels of attraction value equal to those for achromatic light. It was found that the luminance required for the hues tested varied by more than a factor of 4. The results for the attraction value were found to be correlated with modelled equi-brightness predictions.