Re: help with lighting

Jeffrey E. Salzberg (salzberg@flash.net)
Tue, 12 May 1998 04:28:47 -6


> Down-light (from above) reflects on the marley floor back into the lens of
> the overhead camera, sometimes overloading it.

You're up against a law of physics, here: the angle of reflection is
equal to the angle of incidence. The only solutions are:

A. Make the surface less reflective. I have never found a way to do
this that wouldn't make the floor either too slippery or too sticky,
and that wouldn't rub off during the course of the performance.

B. Change the angle of incidence. You've discovered this already;
when you use a different lighting angle, the problem disappears. The
problem with this is that backlight (which I prefer greatly to
downlight) is very, very helpful in separating dancers from the
background -- especially if the dancers are dark-haired and the
background is black. Note that backlight will give you even more of
a reflection than downlight.

C. Move the camera so that the angle of reflection passes over it
rather than directly into it (remember that you can't change the
angle of reflection except by changing the angle of incidence; they
will alway be the same, as any billiards player will attest).
Putting the camera at just above floor level wold virtually eliminate
the problem, but this may not, of course, be practical with your
system.

> front light has no
> reflection problems but creates shadows.

I'm not sure what you mean here, since front light is usually used to
*eliminate* shadows. . .or perhaps you mean shadows on the backdrop
rather than on the dancers? If so, this can be eliminated by using a
vertical angle steep enough (and keeping enough separation between
dancers and backdrop) so that the light can be shuttered off the
background. Note that front light tends to "flatten" dancers out.

> the stage, the angle of the camera is such that the camera does not "see"
> the effect of the near side lights

Side light, of course, is a staple of dance lighting (although I hate
to generalize), as it reveals body shape so well. Can the camera be
farther away (which would change the angle so that it would pick up
more of the "near" sidelights)?

=========================================
Jeffrey E. Salzberg, Lighting Designer
http://www.flash.net/~salzberg
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