Quantifying Natural Light for Lighting and Display Design

Abstract

In natural scenes, the wavelength-dependent sunlight scattering in the atmosphere and the presence of occluders and mutual reflections cause variations in the local illumination's magnitude, direction, and spectral composition as a function of time and space. Yet, unlike the characterization of temporal changes of natural light, these spatial variations have received relatively limited attention. In this paper, we employed the light field concept to quantify those variations and empirically demonstrated that they are significant and how the different contributions of the diffuse and directed parts can be measured.