Light is reflected from each point in all direc-
tions, with maximum intensity perpendicular
to the surface (figure 9.3).
Sand on the beach is an example of a
diffusereflecting surface. There are no bright
spots; the surface appears the same from all
angles of view. In interiors, this quality is
often desirable for walls, ceilings, and work
surfaces. In luminaires, diffusely reflecting
materials are used to produce wide distribu-
tions of light.Reflector Contours
Specular and semi-specular surfaces
formed into geometric contours use thelaw
of reflectionfor beam control: the angle of
incidence equals the angle of reflection. This
is the same law that governs the rebound of
a billiard ball off a cushion.INTERIOR LIGHTING FOR DESIGNERS
Figure 9.2Semi-specular (spread) reflection.Figure 9.3Diffuse reflection.Figure 9.1Specular reflection.Figure 9.4Elliptical contour.