Spectral reflectance luminous efficacy

Abstract

Due to the lack of quantitative evaluation of lighting efficiency and lack of theoretical guidance on spectrum mechanism, there exists huge energy consumption in landscape lighting. This study aims to quantify landscape lighting effect and define efficiency evaluation indicator by studying the relationship between light sources’ spectrum and object's spectral reflectance curves from spectrum aspect. Traditional landscape lighting and Gaussian models of light sources’ spectrum's effect on objects show general rules. Relative high saturated light sources are good for reshaping lighting, while low saturated light sources for reproducing lighting. As most landscapes in a small region are very saturated but less in color types, the concept of spectral reflectance luminous efficacy rather than traditional luminous efficacy is proposed for evaluating landscape lighting efficiency. And comprehensive spectral reflectance luminous efficacy considering weights of landscapes is used to evaluate relative complex scenes. For different landscapes with different spectral reflectance curves, traditional high luminous efficacy lighting may not always achieve better efficiency. For some landscapes, matching light sources’ efficiency would be much higher than traditional light sources. Landscape lighting effect and lighting efficiency could be quantitatively predicted and evaluated.