84 Better Available Light Digital Photography
Real-world color balance
The preceding color-temperature chart places many interior
artifi cial light sources along its value line. You will notice that
household lightbulbs and tungsten lights (usually little spotlights
in track lighting) fall below the Kelvin temperature of daylight.
Fluorescent tubes (becoming more popular by the minute),
mercury-vapor, sodium-vapor, and metal-halide lights are not
even on the chart. That’s because their color temperature can
vary from 1900 K up to 8000 K depending on several factors,
including the age of the bulb. Lastly, don’t forget neon signs,
lasers, computer monitors, and television screens. All of these
devices produce light of different color temperatures. What a
nightmare! No wonder many of us are unhappy with or don’t
pursue available low-light photography.
In the past, you used fi lm or fi lters to help match the color
temperature of the existing light, but all that’s changed with
digital SLRs. Unlike fi lm, which has one—count ’em, one—
Color Balance per roll, your digital SLR (and even most point-
and-shoot digicams) has several that you can change as the
lighting conditions change. Built-in color correction has long
been a part of shooting video, where the camera’s electronic
circuits can be set to neutralize whites and other neutral
colors without requiring fi lters. “White Balance” is the term
from the video industry that we photographers have been stuck
with, and has been with us since the introduction of real color
photography in 1938.
In-camera color correction is managed by your camera’s
White Balance function, a setting that’s built into all digital
cameras, and uses electronics to neutralize whites and balance
colors—without the need for any fi lters. Digital SLRs work
similarly and are, in some ways, better—for example, they can
check color temperature using the AWB (Auto White Balance)
setting to automatically compensate for the light’s color. The
camera’s White Balance can also be set to specifi c light
conditions, or it can be custom-set for any number of possible
lighting conditions. Filters are rarely necessary, making the asso-
ciated light loss a thing of the past. When set in AWB mode,
cameras automatically correct for the light’s color, or White
Balance can also be manually set for specifi c light conditions,
including Daylight, Shade, Cloudy, Tungsten, Fluorescent,
Flash, or Manual.
Auto White Balance is not perfect. Sometimes a scene just
doesn’t look right if automatically corrected. Applying a neutral
balance to a warm sunrise and sunset just looks unrealistic.
That’s just one reason why Automatic White Balance occasion-
ally produces unacceptable results. If you want the effect of the