truly flat: minor surface imperfections such
as trowel marks, tape, and nail-head
depressions are magnified by the shadows
that result from grazing light.
Conversely, diffusewash lightreduces
the likelihood that surface flaws will be
noticed and strengthens an impression of
surface smoothness. This is more suitable
for a gypsum board wall or an acoustical tile
ceiling. Diffuse wash light from the front is
particularly successful at reducing or remov-
ing shadows and small variations in bright-
ness (figures 3.23 and 3.24).
Concentrated directlighting on objects
produces drama and emotional excitement.
Yet the same sharp shadows that contribute
to the dramatic impact also reduce visibility
of detail. This diminishes the ability to study
and appreciate all aspects of the object
accurately (figure 3.25).
A diffuse lighting distribution, on the
other hand, illuminates the entire object,
reducing shadows and facilitating study of
workmanship and detail. Although it is often
desirable, this kind of lighting sacrifices the
dramatic impact and visual excitement
(figure 3.26).
Sharp highlights and dark shadows
create a dramatic setting and strengthen
impressions of texture and form; however,
they are distracting in a working environ-
ment. Some shadows on a work surface are
mildly irritating, such as those cast by a hand
or pencil while one is writing under a concen-
trated light source.
Other shadows are extremely distracting
and even hazardous, such as those on an
assembly line. During a period of sustained
visual activity, the extreme concentration
and constant reädaptation required by work-
ers in high contrast settings result in visual
fatigue, errors, and accidents.
Sometimes highlight and shadow are
desirable in a work environment. Just as the
highlights and shadows of a sunny day are
emotionally stimulating, carefully placed
highlights and shadows in an interior provide
visual relief and interest. Office and factory
workers benefit from the stimulation and
variation provided by greater brightness con-INTERIOR LIGHTING FOR DESIGNERS
Figure 3.25Sculpture lighted with concentrated direct
lighting from below.
Figure 3.26Sculpture lighted with diffuse lighting from
above.