Front projection effect

Front projection versus other techniques[edit]

Compared to back projection, the front projection process used less studio space, and generally produced sharper and more saturated images, as the background plate was not being viewed through a projection screen. The process also had several advantages over bluescreen matte photography, which could suffer from clipping, mismatched mattes, film shrinkage, black or blue haloing, garbage matte artifacts, and image degradation/excessive grain. It could be less time-consuming, and therefore less expensive, than the process of optically separating and combining the background and foreground images using an optical printer. It also allowed the director and/or director of photography to view the combined sequence live, allowing for such effects to be filmed more like a regular sequence, and the performers could be specifically directed to time their actions to action or movement on the projected images.


However, advancements in digital compositing and the increasing use of digital cameras have made digital the most common method of choice. The last major blockbuster to extensively use front projection was the Sylvester Stallone action thriller Cliffhanger from 1993. More recently, the film Oblivion made extensive use of front projection (though not retro-reflective) to display various sky backgrounds in the home set. Spectre also used this technique for its snow mountain hospital and glass building interiors. The advantages for the in-camera effect were a reduced need for digital effects and green screen, interactive lighting in a reflective set, and to provide a real background for the actors.