When mild-mannered reporter Clark Kent became the Man of Steel in Superman (1978), he was made to fly through the sky over Metropolis – through a technique called front projection.
It is the reverse of back projection. The background scene is projected onto a screen behind the actor. But it is beamed from the front. So how do they avoid the background scene showing on the actor?
A projector bounces a low-intensity background image, too dull to show on the actor, off a mirror, angled between projector and camera. The image is reflected back at the camera from a screen, the surface of which is composed of glass beads,. Which intensity the image. Because the light from the screen travels in straight lines, the actor’s shadow is masked by his body.
In the Superman flying sequences, the actor Christopher Reeve was supported by a hydraulic arm protruding fro the screen. Like his shadow, the arm was concealed from the camera by his body.
Zoom lenses on both camera and projector provided the illusion of movement and perspective.
One of the first film makers to use front projection effectively was Stanley Kubrick in 2001: A space Odyssey (1968). It provided the background scenery in the opening sequence of ape men.
Picture Credit : Google