2009

Intensity group
These controls specify the strength or brightness of photometric lights in
physically based quantities.
You set the intensity of a light source using one of the following units:
lm (lumen) Measures the overall output power of the light (
luminous
flux
on page 8029). A 100-watt general purpose light bulb has a luminous
flux of about 1750 lm.
cd (candela) Measures the maximum
luminous intensity on page 8029 of
the light, usually along the direction of aim. a 100-watt general purpose
light bulb has a luminous intensity of about 139 cd.
lx at (lux) Measures illuminance on page 8009 caused by the light shining
on a surface at a certain distance and facing in the direction of the source.
The lux is the International Scene unit, which is equivalent to 1 lumen
per square meter. The AS unit for illuminance is the footcandle (fc) which
is equivalent to 1 lumen per square foot. To convert from footcandles to
lux, multiply by 10.76. For example, to specify an illuminance of 35 fc,
set illuminance to 376.6 lx.
To specify the illuminance of a light, set the lx value on the left, and then
in the second value field, enter the distance at which that illuminance is
measured.
NOTE You can obtain these values directly from lighting manufacturers. A table
of some common lamp types is provided in
Photometric Lights: Common Lamp
Values
on page 5014.
Dimming group
Resulting Intensity Displays the intensity caused by the dimming, using the
same units as the Intensity group.
Dimming percentage When the toggle is on, the value specifies a multiplier
that dims the intensity of the light. At 100 percent, the light has its full
intensity. At lower percentages, the light is dimmed.
Incandescent lamp color shift when dimming When on, the light
simulates an incandescent light by turning more yellow in color as it is
dimmed.
Photometric Lights | 5039