340 Video Digital Communication & Production
Copyright Goodheart-Willcox Co., Inc.
Ceiling Bounce
The low ceilings of many interiors
can actually be a plus because they make
it easy to bounce fill light down onto
subjects and background. Too much ceiling
bounce, however, puts shadows under
subjects’ eyes and resembles institutional
grid lighting, such as ceiling fixtures in
classrooms.
Hiding Lights
Small interiors often make it difficult
to keep the lights out of the frame. Light
stands work well in front and to the sides
of the action area, where they are safely
off screen.
Study your monitor very carefully for cables, which
have a way of creeping into the shot.
To hide lights placed deeper in the set,
deploy units that can be clipped or taped to
moldings, curtain rods, door frames, or the tops
of open doors. Fluorescent ceiling grids are
also prime locations for clipping small lamps,
Figure 16-14.
Some lighting instruments have built-in clips or
clamps; others mount on posts that can be fitted
with clips, clamps, or flat surfaces for mounting.
Calculating Power Draw
The formula says that the amperage (size) of
a power load (in this case, a video light) is equal
to the wattage of the load divided by the voltage
of the circuit, or
Amps =
Watts
Volts
It can be difficult to mentally calculate the amps
used by a video light (and hence, the ability of an
electrical circuit to take the load). Although North
American current is nominally 110 volts, the actual
voltage in a particular circuit may range from 105
to 130, and typically runs around 115–125. Without
troubling to test each circuit, you cannot tell what
its true voltage may be. Also, mentally dividing by a
number such as 117.5 volts is not easy.
To solve both problems, divide by an
arbitrary 100 volts simply by moving the decimal
point. For example, a 750 watt light would draw
7.5 amps (750 watts divided by 100).
This not only simplifies the head math, it also
builds in an automatic safety factor since the
nominal amperage will always be lower than the
actual. For example, at a true 110 volts, a 750
watt light really draws 6.8 amps, not 7.5.
Figure 16-14. Small lights can be gaffer-taped to walls or supported almost anywhere. Larger lights can be clipped
or clamped to anything that is available.
Taped to a wall Clamped to a partial wall Clamped to a chair
Lowel Light Inc. Lo el Light Inc
On the other hand, the gentle spill from
umbrellas or softboxes often makes a very
agreeable background light.