KIM’S STEREO PHOTOGRAPHY PAGES
What is stereo photography ? With a stereo photograph the viewer’s two eyes are presented with two slightly different images, just as the eyes would see when viewing a natural scene. Because the point of view of the two images is slightly different, the brain is able to obtain information about the ‘depth’ of the scene, and in a well done stereo photograph the three dimensional effect is very apparent. ViewMaster slide viewers are probably the form of stereo photography that is most familiar to people. Here, hand drawn images are displayed in pairs through a binocular viewer. In most of the views the stereo effect is quite dramatic. I became interested in making my own stereo photos. It is really quite easy.
Viewing stereo images: There are several different ways of presenting stereo images, and most methods require a kind of viewing device in order to be able to see the stereo effect. The type of viewer depends on the presentation format of the stereo image. (I think this need for a viewer is a main reason stereo photography has not become more popular. Sharp of Japan has developed a method of displaying stereo images on a modified computer screen. The Sharp screen is also usable for viewing standard 2D or ‘flat’ material. If these monitors reach the popular market it should provide a real boost to the field of stereo photography.)
Formats and viewers that keep two separate images: These formats and viewers present two different left and right images usually side by side. Some people are able to view these images without aids, but most folks, especially beginners, will need some sort of viewer that will help merge the two images. Most of the images on this site are intended for use with the sort of viewer distributed by the National Stereographic Association for use with the images in their magazines. http://www.stereoview.org/
These and many other kinds of viewers are available from Berezin as well. http://www.berezin.com/3d/Default.htm
As long as I have them available, I will send out free of charge a viewer suitable for the images on this site to anyone who sends me an email request that includes their mailing address.
Other types of viewers are made to work with transparencies instead of prints, and a different variety that is better for landscapes is also commonly seen. The landscape viewer mounts the stereo pairs in an over and under configuration so that short wide prints can be viewed.
Formats and viewers for single images: Two major variations have been developed that eliminate the need to print two different images. The first method is called ‘anaglyph’. This method uses red and green lenses in the viewing glasses and is the most common format for the stereo movies and comic books that appear occasionally. In this case the two images are processed in such a way that the reds are enhanced in the left image and the greens are enhanced in the right image. Then the two modified images are merged into a single image that contains right and left information. The glasses separate the images again, and the brain merges the jumbled up colors to form a reasonably natural colored perceived image. Recently Anaglyph technology has advanced greatly thanks to the availability of computer based image manipulation software. These sites describe methods to make your stereo pairs into anaglyphs:
Until recently anaglyphs have suffered from poor color saturation and fuzzy definition, and purists tended to avoid them.
Lenticulars are another method that permit viewing of stereo images without a special viewer. Lenticular technology involves making an image which has been specially prepared by taking the two images of the stereo pair and cutting them into narrow vertical strips and then assembling the strips into one image with alternating left and right part strips. This image is then mounted behind a plastic sheet which is formed into vertical strip lenses which separate the alternating left and right strips and send them to the two eyes. National Geographic and other magazines will occasionally do a stereo cover using this method. Lenticular technology is also used to make those cards and now highway signs that show two different images depending on the viewing angle. Lenticular is capable of very fine looking results that require no viewer. It is the basis of the Sharp computer stereo display mentioned earlier. Unfortunately lenticular technology is out of the reach of most hobbyists because the high initial set up charges associated with lenticular image production means that they are only economical when production volumes approach 100 or more identical copies. This site offers instruction, materials, and conversion to lenticular format. There is also some good basic stereo theory on this site: http://www.didik.com/varivue/
More of Kim’s stereo images : http://www.falconlabs.com/3D/3d_1.htm