Diffuseness of illumination suitable for reproducing a faithful and ideal appearance of an object

Abstract

We investigated the diffuseness of illumination to examine which diffuseness condition faithfully reproduces the surface appearance of an object as seen in a natural environment. We also examined the diffuseness condition which produces the ideal appearance of the object. Observers first memorized the appearance of various objects in daily environments, and then evaluated the appearance of the objects under different diffuseness conditions. The observers reported that the moderate diffuseness condition best reproduced a faithful and ideal appearance of the objects, compared with the low and high diffuseness conditions. This indicates that a very low or high diffuseness, which is unfamiliar, is not suitable for reproducing an object’s surface appearance faithfully and ideally. Our results suggest that it is possible to determine a suitable diffuseness condition for reproducing the appearance of objects.