A Brief History of Anaglyph

Anaglyph images are used to provide a 3D effect, when viewed with 2 color glasses (each lens a chromatically opposite color, usually red and cyan). Images are made up of two color layers, superimposed, but offset with respect to each other to produce a depth effect. Usually the main subject is in the center, while the foreground and background are shifted laterally in opposite directions. The picture contains two differently filtered colored images, one for each eye. The visual part of the brain merges this into perception of a three dimensional scene or composition.
Anaglyph images have seen a recent resurgence due to the presentation of images and video on the internet, blue ray HD disks, CDs, and even in print. Low cost paper frames or plastic-framed glasses hold accurate color filters that typically, after 2002, make use of all 3 primary colors. The current norm is red for one channel (usually the left) and a combination of both blue and green in the other filter. That equal combination is called cyan in technical circles, or blue-green. The cheaper filter material used in the monochromatic past, dictated red and blue for convenience and cost. There is a material improvement of full color images, with the cyan filter, especially for accurate skin tones. Video games, theatrical films, and DVDs can be shown in the anaglyph 3D process.