that combines an ellipse with a parabola (fig-
ures 12.25 through 12.27) or they use non-
focal shapes. Open-reflector wall-washers
require a point source with a compact fila-
ment; they are available for tungsten-halogen
T3 and T4 and ceramic metal halide T6 lamps.
Lensed and open-reflector wall-washers
used without downlights provide a shadow-
less, low-contrast setting. When people are
distant from the lighted wall they are seen as
flat-featured; people next to the lighted wall
are seen as silhouettes. These problems are
avoided by adding downlights.
Wall-washing is also produced by dif-
fuse-source, fluorescent-lamp wall-wash
systems. The inability of a diffuse source to
project a high intensity toward the bottom of
a wall usually results in a bright area at the
top of the wall and a rapid falloff of lumi-
nance thereafter. Sophisticated reflector
systems with a wide aperture help to solve
this problem (figure 12.28). Fluorescent
wall-wash systems, sometimes called “per-
imeter” wall-wash systems, are more
energy-effective than their incandescent
counterparts.INTERIOR LIGHTING FOR DESIGNERS
Figure 12.25Recessed tungsten-halogen T4 wall-washer.