Datasheet

28
c h a p t e r 1: UNDERSTANDING LIGHTING, COLOR, AND COMPOSITION ■
Candlelight 1900 K
7500
7000
6500
6000
5500
5000
4500
4000
3500
3000
2500
2000
1500
North light (blue sky) 10000 K
Overcast daylight 7000 K
Daylight metal halide bulb 5500 K
Noon daylight, direct sun 5000 K
Cool white fluorescent 4200 K
Metal halide bulb 4000 K
Clear flashbulb 3800 K
Sunset/sunrise 3100 K
Halogen bulb 3000 K
Standard incandescent 2700 K
High-pressure sodium bulb 2200 K
Figure 1.33 Color temperatures of common light sources. This image is
included on the CD as
color_chart.tif.
Setting a White Point
In the case of monitor calibration, color temperature is used to set the white point
of the hardware. A white point is a coordinate in color space that defines what is
“white.” If a monitor is given a white point with a high kelvin value, the display has a
blue cast. If a monitor is given a white point with a low kelvin value, the display has
a yellow cast. The flexibility of the white point is necessary to match potential output
formats. For example, graphic artists who use offset printing might set their monitors
to 5500 K. For 3D animation intended for video, 6500 K generally works because
broadcast-quality video monitors have a hardware white point set to 6500 K. In con-
trast, older consumer televisions may have a white point set as high at 9300 K. Many
plasma and LCD televisions now offer the option to switch to 5400 K to better match
motion picture film.
When lighting in Maya, you do not need to know the kelvin temperature of a
light source. What is important, however, is that the color of the light logically fits the
type of source. For example, daytime sunlight varies from white to blue. Firelight var-
ies from red to orange. Incandescent lightbulbs are yellowish. If a light color is out of
place, a scene may appear incorrect to the viewer. This should not be confused with
the way colors are recorded on film, where colors are often exaggerated. For example,
daylight film (balanced for 5500 K) will make the yellow of an incandescent bulb
more orange. Tungsten film (balanced for 3200 K) will make sunlight extremely blue.
Professional photographers and cinematographers reduce this problem by employing
color corrective filters and gels. However, the end result is rarely the same as the way
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