As part of our production capabilities we have had to devise “shadow shows” at various events in the past. These are performances that utilize a backdrop onto which the shadow of the performer is cast, usually from behind the backdrop. Producing this effect properly, however, can present some technical challenges with which we’ve had to contend: The light source must be a single point source. Incandescent or quartz lamped fixtures work well.
Multiple fixtures or fixtures with multiple sources grouped together (such as most of the LED fixtures out there) will cast multiple shadows onto the backdrop. The backdrop must be translucent enough to allow light transference but ideally should be designed to diffuse the point source or “hot spot” of the lighting fixture. Some people are okay with muslin or a similar fabric (think heavy duty bed sheet), but muslin tends to allow the point source to be seen as a hot spot.
Rear projection screen is a good choice, but may be economically unfeasible. Lastly, the performance must be contained to a fairly small area unless distortion of the shadow, similar to the keystone effect with video projection, is acceptable. In some shows we have seen, this distortion was made part of the show for additional impact. The farther the light source is from the backdrop, the less distortion there will be over a given area. -VAR