Although a moon effect can be produced by projecting a gobo onto a backdrop, a more realistic effect can be achieved by using a light box.
The front of the box is
cut
out in the desired moon shape. The cutout is covered with a translucent material, such as a heavy diffusion filter, and can be also fitted with color filters. A number of lamps are fitted inside the box, in such a manner that the light merges and the separate sources are not visible. As the
moon box
is usually hung behind the backdrop the light must be strong enough to shine through the backdrop. Moving the
moon box
across a
skycloth
creates a spectacular and very realistic effect.
The same technique is used for light boxes simulating other lit elements such as neon signs, lit windows in a distant building and so on.
