Every situation has unique lighting requirements,
of course, but Figure 16-45 illustrates a solution
for a typical tabletop setup. The subject and
tabletop are bracketed by very large, bright
fl uorescent softlights. These instruments are
excellent for this application because:
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Their 4′ square shape provides an extremely
large source to reduce shadows.
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Their multiple 40-watt tubes provide a bright
light, permitting smaller f-stops to create
greater depth of fi eld.
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Their power requirements are low enough
for use in most locations.
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Their output is cool enough for subject comfort
and for delicate applications, such as food
demonstrations and biology experiments.
LED arrays are even cooler and consume
less power. Because their light is not as soft,
however, they may need added diffusion for
truly shadowless lighting.
Tenting
Where you want completely shadowless
lighting (and do not require great depth of
fi eld), you can use tent lighting. By hanging a
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The hands, arms, and head of the
demonstrator tend to get into the picture.
To help solve these questions, you need lights
that are both very bright (to force smaller lens
openings and thereby increase depth of fi eld)
and very soft (to eliminate or at least minimize
shadows in the picture).
Permanent Compositing Studios
Green screen backgrounds that include floors
permit the use of “virtual” sets—complete digital
environments into which subjects can be composited.
In this studio setup, more than 20 one-foot LED
arrays on overhead pipes are used to light the
upper part of the background. Large arrays, like
the 16-panel floor unit pictured on the right of the
studio setup figure, cover the lower walls and floor.
Smaller units, like the single and four-panel arrays
stored on the left of the studio setup figure, are
moved into position to light subjects in the foreground.
LED arrays are very useful in compositing
applications where large numbers of lights are
required for uniform coverage because they emit
almost no heat, they can be balanced by adjustable,
remote controlled dimmers, and they consume so
little power. When this studio uses 50 panels, all
of the panels together draw 2,000 watts.
To achieve a comparable light output with
halogen lights would demand over ten times as
much power—not counting the wattage of the air
conditioning needed to counteract their heat.
A permanent compositing setup.
(Litepanels, Inc.)
Figure 16-44 A tabletop shot.
(Photoflex)
358 Video Digital Communication & Production