Scified FX - What is Process Photography?

Hollywoods over reliance on Computer Generated Imagery, or CGI, is starting to have a negative impact on the creativity and likely the profitability of recent movies. One prominent example was 2011's prequel to John Carpenters classic 1982 horror movie of the same name, The Thing. For the 2011 prequel Amalgamated Dynamics, founded by Alec Gillis and Tom Woodruff Jr., created the majority of the movies monster effects, but in post production these practical effects were replaced with virtually identical, yet cheaply produced CGI courtesy of Canadian company Image Engine. Had the original practical effects been showcased instead the movie would have, at the very least, remained faithful to the spirit of the visual effects style of Carpenters cult classic original.

CGI has become so commonplace and so cheap to produce that it has become the “go-to” default for visual effects in most recently released movies, regardless of a movies budget. Unfortunately CGI is a relatively new tool in a directors arsenal of film making tools, and often fails to effectively create the imagery it is intended to represent. Yet studios and executives favor this new technology over more traditional, practical visual effects, considering it to be more reliable and more economic against a movies budget.

Thankfully there has been a recent resurgence in the return of the use of practical visual effects spearheaded by renowned directors such as Sir Ridley Scott, J.J. Abrams and George Miller, each of which have proved that not only do practical visual effects still have a place in Hollywood movies, but also that in most cases the result, when executed effectively by a talented team of visual effects artists, engineers and puppeteers can be more effective and more believable than its comparative CGI effect.

Scified FX is a new series of articles that will showcase these practical visual effects, how they are used and the masters that have created them. In this article Scified FX takes a look at the commonly used technique known as Process Photography, a cheap and relatively easy technique that is still used to this day.

Process Photography

Process Photography in cinema is a visual effect that can be achieved through many techniques in which two or more layers, or plates, are used together to create the illusion that each plate exists in the same space.

An early example of Process Photography would be the widely used rear, and front, projection technique in which a scene would be enacted in front of canvas onto which pre-recorded footage would be projected, from either behind or in front of the canvas. This technique has often been used in cinema and TV to create the illusion of a car moving in traffic while focusing on the performance of the actors in the foreground. While rear projection was a relatively easy and cheap effect, the resulting background plate would often appear washed out and blurry, but whereas front projection produced a clear and vibrant image on the background plate constructing the effect proved more difficult. Both rear and front projection however suffered from the same issue, in that despite the best choreography the actors actions would often be out of sync to that of the background imagery. Movies that have used this technique include Aliens, The Terminator, Terminator 2: Judgment Day and 2001: A Space Odyssey. Developed during the golden age of cinema, rear and front projection would continue to be used well into the 90's, but a decade earlier a new form of Process Photography would take over the world of both TV and movies.

Chroma Key Compositing is a form of Process Photography in which a scene is enacted in front of a colored canvas, then by making transparent anything in the shot matching the color of the canvas, in its place a full color background plate can be added. During the 80'sand 90's this technique, more commonly known as “Bluescreen”, was used to great effect for morning TV news weather reports, and while since the turn of the millennium “Greensreen” has become more common with the rise of digital editing and compositing the little known “Redscreen” has been used in the past to great effect; “Redscreen” Compositing was often used by the late visual effects legend Ray Harryhausen to composite his iconic stop motion creations into a live action frame.

Process Photography shares many similarities to Matte Photography, which also creates a scene using composite layers. Although many techniques used to create Matte Photography rely on the use of static background and/or foreground layers, the advances in optical and digital compositing have allowed for the compositing of multiple, moving layers.