ABSTRACT
One method of overcoming the lack of parallax, and at the same time avoiding the necessity for wearing special glasses, is the parallax stereogram. e technique for producing these involves moving a camera past the subject matter (or moving the subject matter past the camera) while you take several photographs at angular intervals of a few degrees. You then need to extract narrow vertical stripes from each image, print them interlaced on paper, each in its correct geometrical position, and mount on the print a vertical lenticular screen, in such a way that each vertical lenticule lies precisely over a single set of vertical stripes derived from the original photographs. e lenticules direct the image of each stripe in the appropriate direction, allowing the viewer to see a single image from any one viewpoint. You can thus view the result without any optical aids and see genuine horizontal parallax over a (limited) range of angles. Such autostereograms (i.e., stereoscopic images that you can view without any optical aid) enjoy some success in the picture postcard and poster industry-and, recently, enormous success in the Asian mobile phone market. From time to time cameras embodying similar principles appear.
