Interior Lighting for Designers

Uplighting systems also increase the ver-
tical illumination in a space. While this is
desirable for many surfaces, it reduces image
contrast on VDT screens. Although indirect
lighting systems eliminate the most offensive
image glare common with direct lighting on
VDTs, they may introduce less-problematic
veiling reflection and contrast reductions on
the surface of the screen.

A well-designed indirect luminaire has a

wide distribution. Multiple luminaires are

located so that their light output will be

evenly distributed across the ceiling without

hot spots or areas of high luminance (fig-

ure 13.21). The goal is uniform ceiling

brightness, where luminances and lumi-

nance ratios are consistent throughout the

space.

DESIGN

Figure 13.20Some areas have noticeable shadows from office partitions,

especially when partitions are located on three sides of the work surface.

Figure 13.21Above, properly located indirect luminaires with wide distributions produce even luminance; below, improp-
erly located indirect luminaires with narrow distributions produce areas of uneven luminance.