ABSTRACT
Illumination is to the eyes what air is to the lungs. Everything that we see, we see ultimately because it is illuminated by some source of light, whether it be the sun, a candle, or light reflected from nearby surfaces. By changing the illumination conditions, it is possible to considerably alter the subjective appearance of an object, as can be seen in Figure 9.1. Unsurprisingly, artists are acutely aware of this and have a sophisticated vocabulary for describing the qualities of lighting and its effects within a scene. Painting, sculpture, photography, and architecture all use light in a variety of ways to create moods, to mold the spaces between things, and to draw attention to or conceal details.
