Director Richard Donner knew the film would only work if Christopher Reeve could convincingly fly. He therefore asked his team to invent a new method to achieve this challenge, as nothing that existed before would be suitable.
The person who found the solution to the problem is Zoran Perisic. This optical effects specialist, who had worked on 2001: A Space Odyssey , invented a process for the occasion, called Zoptic .
In short, without going into too much technical detail, it's a complex device that projects a film of a landscape (for example, a New York City backdrop filmed from a helicopter) onto a large screen in front of which the actor stands. This device also includes a camera that films the actor in front of the screen. So far, nothing exceptional. What is exceptional about this setup is that the camera filming the actor is synchronized with the projector displaying the background, so that the camera filming the actor can, for example, zoom in on him without affecting the background.
Thus, to give the impression that Superman is accelerating, the camera can zoom in on him without zooming in on the background. That's the secret of this optical illusion.
The two images are superimposed, but one can act on the foreground without affecting the background.
This system also allows the camera to rotate around the actor without the background moving, giving the impression that Superman is spinning around.
Christopher Reeves and Margot Kidder lying on a pedestal that will not be seen on screen.
Nevertheless, this method proved very time-consuming to implement. Five months were needed to film the flight sequences for the movie…
Note that for all landing and takeoff sequences, Christopher Reeves was simply held by cables and attached to a crane that lifted him off the ground.