Spatial and form-giving qualities of light

This chapter addresses the spatial and form-giving qualities of light, or the awareness of the spatial structure of the luminous environment, from a multidisciplinary perspective. The luminosity framework is of major importance. Whereas the chronogeometrical framework has to do with the where and when of visual objects and events, the luminosity framework has to do with the what and how questions, that is to say, with material constitution, surface corrugations, and appearance, as opposed to location and shape. The luminosity framework figures prominently in the visual arts. The chapter focuses on the perception of the luminous environment: how to measure the subjective luminosity framework, as opposed to the objective, radiometric luminous environment, how to describe this framework using quantitative descriptive methods and standardized terminology, and how to relate these formal descriptions to semantic descriptions of light by non-professional observers.