ping lamps achieve the same result (figure
12.40).
When space constraints limit the cove
design so that the source is located too
close to the adjacent wall and ceiling, these
surfaces will appear excessively bright.
Shields can be incorporated into the cove
design to intercept some of the light and pre-
vent it from reaching the upper wall. The
upper wall will be lighted by reflection from
the cove lip and ceiling, reducing the light
gradients (figure 12.41).
To ensure uniformity on the ceiling plane,
the distance from the center line of the lamp
to the ceiling must be a minimum of 12 in for
rapid-start lamps and 18 in for HO and VHO
lamps. Curved transitions between adjacent
surfaces will produce more gradual, softer
gradients (figure 12.42).
The height of the vertical shield or “lip”
of the cove is determined by asight line
analysis. On a section drawing through the
cove, draw a line between a viewer’s eye,
located at the farthest viewing point, and the
edge of the cove lip (figure 12.43). The lip of
the cove is designed to shield the lamp at
normal viewing angles but must not interfere
with the distribution of light across the ceil-
ing (figures 12.44).
When incandescent directional sources
are used in a linear array, the beam axis is
aimed at a point two-thirds of the way across
the lighted surface. This provides relative
uniformity of illumination (figure 12.45).Object Lights
Adjustableobject lights, sometimes impre-
cisely called “accent lights,” provide a sym-
metric distribution of light aimed at one or
several objects. They use a directional source
such as an AR, MR, PAR, or R lamp. Also
called “spot lights,” they are used to provide
focal glow and add contrast to a setting.
Recessed, adjustable, object lights may
have a horizontal rotation stop to prevent
wires from tangling as the lamp is rotated.
Vertical adjustment is from 0° to between
35° and 45° (figure 12.46). Surface-, pen-
dant-, and track-mounted luminaires have a
greater range of vertical adjustment than
recessed equipment (figures 12.47 and
12.48). The best track-mounted adjustable
object lights are designed to rotate slightly
more than 360°; inferior luminaires have aINTERIOR LIGHTING FOR DESIGNERS
Figure 12.38A 1:4 placement ratio is applicable when light is emitted from one side only. A 1:6 ratio is
applicable when light is emitted from two or four sides.