Front Projection Effect System

Front Projection effect is a technique similar to green screening but it’s done in camera instead of in post-production compositing.  The camera is able to combine both the subject and the background image in one shot.  It’s becoming a lost art of film making due to the popularity of low cost CG effects and compositing with green screens.

How it works:

By Wikiwikiyarou (Own work) [CC BY-SA 3.0

By Wikiwikiyarou (Own work) [CC BY-SA 3.0

A transparency projector or motion picture projector  and a special retro-reflective lenticular screen (made of Scotchlite) is positioned behind the action and acts like a backdrop.  Scotchlite is a material made by 3M that is made of tiny glass beads that do a fantastic job of reflecting the light.  To set it up you have to reflect a projection off a one-way mirror and then onto the backdrop. It fills the camera’s filed of view and oriented at a precise 45 degrees of the shooting axis. Then the camera films the non-reflective side fo the one way mirror and sees a composite shot, all without using a computer!  The setup can be pretty complicated to do and setup but once you have it done correctly you’ll be impressed at what a low tech solution can do, and it can give you a nice retro look if that’s what you are going for.

There are some other interesting techniques that were used to advance the basic concept of front projection.  For the film Superman: The Movie (1978) a cameraman by the name of Zoran Perisic devised a method of electronically motorized lenses.  The Wikipedia page has some other good information as well as some other specific techniques that were developed.