> We wish to construct a light show and project it on to a high ceiling and high
> side walls in the main lobby of a museum. The graphics will be silhouettes of
> Chinese characters and dragons. We wish these to "dance" over the heads of
> viewers.
> I know that there are expensive ways to do this with computers, etc..
> But does anybody know of a simpler manner that would consist of a stencil cut
> out revolving around a light source?

In our planetarium, we often use simple 'brute force' projectors for
similar effects.  A typical example is the common planetarium 'cloud'
projector.

What you need to do is find a light source that is as close to a
point-source as possible.  We've had best luck with low-voltage signal and
automotive lamps.  The idea is that you want a *really* short fillament.
If the fillament is too long, this won't work well, and the images will be
very fuzzy.

What we usually do is put the lamp inside a rotating plexiglas dome, and
paint the images we want to project on the outside.

Another technique is to have the images on a lazy susan, and spin the disk
in front of a window with the lamp behind it.

-j