http://www.ray3dzone.com/SK.html

See the above site for the whole article - quite a good bit of information there for those creating both still and moving anaglyph style 3d images.

Good Old-Fashion Anaglyph

Robert Rodriguez Uses High Tech Tools to Revive a Classic Format with Spy Kids 3-D

By Ray Zone

Some people just don't like anaglyph. Viewing the world through complementary colored glasses, red and cyan, is just too much retinal bombardment for them. But the anaglyph continues to fascinate filmmakers and artists as a viable way to display stereographic imagery. Director Robert Rodriguez, creator of the popular Spy Kidsmovie franchise, is the most recent case in point.

A Little Red/Blue History

Anaglyphic motion pictures have a varied and intermittent history that goes back to the Nickelodeon era of cinema when filmmakers and audiences were first discovering the story telling capabilities of the new technological art.

The projection of anaglyph images using complementary colors was first attempted and described by Wilhelm Rollman in Germany in1853. In 1891, Louis Ducos du Hauron of France patented and named the system of the "anaglyph" and it was used at that time both for printing and projection of lantern slide shows.

The first public presentation of anaglyph motion pictures in America took place on June 10, 1915 at the Astor Theater in New York with anaglyphic sequences in the film Jim the Penmanphotographed by Edwin S. Porter with the assistance of William E. Waddell. Two anaglyphic travelogues, Niagara Falls and Rural America,were also on the program. It seems likely that Porter and Waddell used a twin interlock projector system with two black and white film strips projected through red and green filters. The audience, of course, was equipped with anaglyph spectacles to view the films.

Jim the Penman (1915) - Anaglyph Projection

When Technicolor introduced their two-color cemented film positive process in 1921, Frederic Ives and Jacob Leventhal, under their Educational Pictures banner, produced a number of short films in the single-strip process and named it Plastigrams,the title of their first production. Other anaglyphic shorts, Zowie, Luna-cy, Ouch!and The Runaway Taxiwere released by Ives and Leventhal in 1925 through the Pathe studios. An interprising producer, Harry K. Fairall released an anaglyphic feature, The Power of Love,in 1922 in Los Angeles which gave the audience the option of viewing two different endings to the film through either the red or green lenses of the spectacles.

"The problems involved in producing anaglyphs in natural colours have claimed the attention of many workers," wrote Leslie P. Dudley in his 1951 book Stereoptics, An Introduction,"and various processes for the production of so-called polychromatic anaglyphs have been proposed from time to time."

The first full-color anaglyph motion picture appears to be a 1969 adult film called Swingtail. Los Angeles-based producer Steve Gibson's Deep Vision company with the talents of 3-D cinematographer Arnold Herr has also produced seven adult films in polychromatic anaglyph including The Playmates(1973), Black Lolita(1975) and Disco Dolls in Hot Skin(1978), among others.

These polychromatic anaglyph features were filmed with a beam-splitter and color filters directly onto a single strip of Eastman Kodak color stock. The disadvantage of the system is that no adjustment to parallax is possible after principal photography. For the color anaglyph finale of Freddy's Dead: The Final Nightmare(1991) the stereoscopic photography was done with the single strip Stereovision process and then optically printed to anaglyph composite.

Freddy's Deadwas a good example of how notto art direct a color anaglyph movie. Freddy's sweater, for example, consisted of alternating bands of bright red and green stripes. The retinal rivalry that bright red, blue and green induces in the anaglyph is a deficiency that Robert Rodriguez has assiduously avoided in Spy Kids 3-D. The color palette consists of gun metal grey and purple backgrounds, highly metallic surfaces and primary colors that are minimally used. Yellow and purple, light orange and green, carry most of the color design and help to minimize the color flicker through the red/blue glasses.

An additional achievement of Rodriguez's polychromatic anaglyph color design is to stage the action of the actors continuously at the stereo window where minimal color fringing and ghosting is evident. You could even watch the anaglyph sequences in Spy Kids 3-Dwithout the glasses and not experience too much distraction. This is a real achievement for anaglyphic motion pictures which historically have had excessive ghosting and exaggerated parallax that is painful to view.

Stereographic Storytelling

While film critic Roger Ebert remains "unconvinced that 3-D is necessary in cinematic storytelling," Spy Kids 3-D,with a story set in computer cyberspace, creates a natural fit between the narrative and the anaglyphic format. For the audience, as well as the characters in the story, entry into stereoscopic cyberspace is made possible by wearing the red/blue glasses.

A 1961 black-and-white horror film, The Mask,directed by Julian Roffman, featured a similar imaginative use of the anaglyph with three different segments that depicted the subconscious minds of characters in the film. The hypnotic voice of a psychoanalyst in The Mask commanded the audience to "put on the mask now" to view hallucinatory anaglyphic segments. As with The Mask, Spy Kids 3-Dmakes use of the anaglyphic glasses as a metaphoric portal to another world of experience.

It's a challenge for 3-D filmmakers to coherently justify the use of stereopsis within the context of a narrative. "It is a mistake," says Ebert, "when the medium distracts from the message." Quite often the use of off-the-screen effects, the sheer sensory distraction of 3-D, does little to enhance the story. Spy Kids 3-D,however, set within an active arena of cyberspace with floating platforms, outsize weapons and hovercraft motorcycles, uses the stereoscopic parameter as a seamless part of the kinetic narrative.