A vectograph is a type of stereoscopic print or transparency viewed using the polarized 3D glasses most commonly associated with projected three-dimensional motion pictures.
The Polaroid Corporation, founded by Edwin Land, developed a process for making a polarizing filter sheet that encodes a photographic image as areas which polarize light more or less strongly, corresponding to the darker and lighter areas of the image. When the sheet is viewed by itself in ordinary light, a pale image is seen. When viewed through a uniformly polarizing filter sheet oriented in the same plane of polarization, the image is almost completely invisible. If either the viewing filter or the image-encoding sheet is then rotated 90 degrees about its axis, so that their planes of polarization are at right angles to each other, the image becomes boldly visible. By combining two such images, made to polarize in opposing directions and each encoding one of the images of a stereoscopic pair, then viewing them through glasses containing filters polarized in opposing directions, each eye sees only one of the images and a single three-dimensional image is perceived by people with normal stereoscopic vision. Vectographs in their native form are transparencies, to be viewed by transmitted light or projected onto a suitable screen, but by limiting the density of the images and backing the vectograph with an aluminum-based paint which does not depolarize light, it can be used as a print for viewing by reflected light.
The process permitted the creation of prints and transparencies that could serve some of the same purposes as their anaglyph equivalents, but with the visual advantage that they did not require the use of viewing filters which were of disturbingly different colors for each eye. Originally a monochrome "black-and-white" process only, a full-color version was eventually developed. During the 3D motion picture fad of 1953, vectographic 3D prints which could be used in unmodified projectors like ordinary "flat" prints were anticipated, but the rapid waning of public enthusiasm for 3D quashed such plans. Neither the original full-color process nor a more recent ink jet printer implementation of it ever found any substantial commercial use. While anaglyph images could be produced by virtually any photographic or mechanical printing process capable of producing a two-colored image, vectographic images required specialized materials and printing technologies, limiting their practical application.
Perhaps the most common vectographic images are those in the booklets of "Ortho-Fusor" stereoscopic eye exercises marketed by Bausch and Lomb in the 1940s and 1950s, and the Titmus Fly Stereotest, used by Optometrists and ophthalmologists to determine if patients, especially young children, have normal stereoscopic vision. During World War II, some stereoscopic aerial reconnaissance photographs were printed in the form of vectographs, allowing several people to simultaneously view each image in relief during analysis and discussion.
Joseph Mahler (cousin of famed composer/conductor Gustav Mahler) is the inventor of the Vectograph. Mr. Mahler immigrated to the U.S. from Czechoslovakia in 1938 with his wife Anna and two daughters Hana and Helen. He died in Laguna Hills, California in July 1981 at the age of 81.
Around 2000, the Rowland Institute, once part of Polaroid and now part of Harvard University, introduced a modernized version of the technology under the name "StereoJet," but as of 2006, it is unclear whether the technology is available.[1]