ABSTRACT
Painting or photographing a scene on a slide for projection is neither an easy nor a cheap substitute for solid scenery. If projection is embarked upon it must be as a production style, probably because the script demands a wide range of instantly changeable locations and/or the luminous quality of a projected image is appropriate. Projection is often referred to as ‘back projection’ but, unless we use 35mm carousel-type projectors (see below), there is rarely enough stage depth to project onto the screen from behind. Standard projection is more frequently onto the front of the screen and since such projection normally has to be at an oblique angle, the slides need to be specially prepared to counteract the distortion introduced by the angled throw. Scene projectors have special optical systems to produce an even light over the slide area and there are special cooling arrangements, usually involving fans and heat-resistant glasses, to protect these optics and the slide. It is difficult to get enough projected brightness to balance with the actor light, and so scenic projectors tend to be physically big, the more powerful ones using discharge-lamp sources. These use slides up to 24 cm square which can be hand-painted as an alternative to photography.
