Absolute Beginner's Guide to Digital Photography

(Ann) #1
Color Balance and Film
Color film can record colors that your eye does not
see when the picture is made. This is because film is
manufactured to reproduce color accurately under
specific lighting conditions. If the picture is made
under the wrong lighting, colors in the photograph
become unbalanced, which means that there is an
unwanted color tint (or color cast) over the entire
photograph.
For example, if daylight-balanced film is used
indoors under incandescent light bulbs, objects that
are supposed to look white, such as a white shirt,
will be rendered with a red tint. This is because
incandescent light bulbs produce more light in the
red wavelengths than daylight does.

Color Balance and Slide Film
Color balance is more important with reversal film
than with negative film. Because reversal film is viewed directly, any minor color
cast will be noticed. The colors in negative films can be corrected in printing, so neg-
ative films produce acceptable results under a wider range of lighting. Even so, you
get the best colors if film is shot under correctly balanced lighting or if color correc-
tion filters are placed on the lens to correct the color of the light.
The color of daylight changes depending on the weather and the time of day.
Daylight color film is color balanced for average noon sunlight. An hour or two
before sunset, the light becomes very red or yellow. On cloudy days, the color of day-
light becomes much bluer. Color filters can be used to eliminate the bluish color if it
is undesirable.

Exposure Latitude
Color transparency film and most consumer digital cameras have little exposure lat-
itude. Even slight overexposure or underexposure is readily visible, especially in con-
trasting lighting. Consumer-level digital cameras blow outhighlights in overexposed
prints (see Figure 5.2). A blowoutis a dead giveaway the image was taken with a dig-
ital camera.

66 ABSOLUTE BEGINNER’S GUIDE TODIGITAL PHOTOGRAPHY


Fluorescent lamps do
not produce a continuous
color spectrum of light like an
incandescent bulb. Instead, fluo-
rescent bulbs generate spikes of
light at certain wavelengths
within the spectrum, especially
green light. They are generally
considered to be at a temperature
of 4500°K.
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