Stereo

Stereo photography, or stereo in short, is a technique in which a camera, specially designed or modified for this, takes two pictures at the time of the same scene. The two pictures are taken from a slightly different point of view, like the left eye and the right eye in human vision. When the two pictures are viewed with a stereo viewer, the left picture is shown to the left eye and the right picture to the right eye, and that gives a tridimensional effect.

There were two major periods when stereo photography was very much in fashion. The first one was at the beginning of the 20th century, when commercial stereo cameras, such as the Kodak Brownie Hawkeye Stereo (Models 1, 2, 3 and 4), were widely available. The second period started in the 1950s when the Stereo Realist brought on a second boom of stereo cameras. A small resurrection occurred in the mid-1980s when Nimslo and Nashika cameras became available, offering lenticular printing to the general public. Currently, a smaller boom of stereo cameras is happening with new cameras being made, such as the 3D World TTL-120 medium format camera and the Horseman. Because of price, the new cameras are marketed mainly at a professional market rather than the hobbyist.

The main formats for stereo photography at the beginning of the 20th century were 6x13cm and 45x107mm for a pair of glass plate photos. In the 1950s the cameras tended to adopt some variation around the 24x23mm size per picture on regular 35mm film.

Methods of Photography

Stereo Camera

The easiest method is to use a stereo camera. Stereo cameras are made with two or more lenses, depending on the desired output. For most uses, only two lenses are needed. However, for lenticular printing (or use of an autostereosopic monitor), while two lenses can be used, three or more lenses are preferred in order to widen the angle of viewing. This is also one of the best methods for taking photos of objects in motion.

Some stereo cameras are made by joining two or more cameras together. RBT is an example of this type of camera.

Cha-Cha

Cha-cha, also known as the astronaut shuffle, is the method of taking a photo, moving the camera to the right slightly, and then taking a second photo. The disadvantage of this is that this method is only good for non-moving objects, such as a landscape or architecture.

While this can be done freehand, a more precise way of taking a cha-cha photo is to use a slide bar, which will put the camera at exactly the place you need it to be.

Twining

Twining is the act of placing two cameras side by side for the photo. This is usually a good alternative to cha-cha for digital stereo photographers, though it is a more expensive route. Twining bars for various camera sizes are available that will place the lenses level and at the appropriate distance. Then, the cameras' shutters are released simultaneously either manually pushing the shutter release on both cameras at the same time or, preferably, using a modified cable release that will sync that two cameras.

Types of Stereo

Most stereo cameras will try to mimic the distance between the human eye. However, the human eye is insufficient for some photography.

Macro Stereo

With a macro stereo, lenses are placed very close together in order to take a photo of very small subjects in stereo. With cha-cha, this can be achieved by moving the camera over only very slightly or rotating the object slightly. Macro stereo cameras have been made by RBT and David White Co.

Hyperstereo

This method can only be done with cha-cha or twining as the distance needed for a hyperstereo photo is much wider than a human eye. Hyperstereo is best for landscapes and cityscapes where a normal stereo photo would show absolutely no depth. Distance between two cameras depends on the subject. For example, doing a cityscape might only mean that you would need to take two photos on a roof with one camera at each end of the building, thus creating a lens separation of several feet.

Viewing and Presentation Methods

Stereo Cards

One of the oldest methods is a printed photo. These were very popular in the late 19th century up until the 1940s when View-Master became the popular format. For medium format photography, this method only requires a contact print.

Stereo Slides

The most popular method, stereo slides are slides that are mounted in a stereo mount, such as a Realist-format mount or a View-Master reel.

Anaglyph

Requires a pair of glasses, but can be viewed in print, on a monitor, or projected. Glasses in anaglyphs are usually tinted red and cyan, but red and green or red and blue are other options. This is the method that most people mistakenly associate with 3-D movies of 1953 (most movies produced in the 3-D movie boom of 1953 were polarized stereo). The disadvantage of anaglyphs is that the red tinting of the glasses gives many people eye strain or headaches after extended use.

Lenticular Printing

This method is capable of free-viewing without the need for a viewer or glasses. In lenticular prints, multiple images are interlaced and then a plastic sheet is placed on top of the print. This is a popular method for movie posters, advertisements, and other areas where glasses or a viewer might not be desirable. Also frequently used to show simple animations.

Projection

Projection is usually done by twining a pair of projectors or by using a stereo projector. The lenses of the projector are polarized so that when the polarized glasses are worn, they will give a very clear representation of the picture. However, a normal screen cannot be used. Only a silver screen is capable of the projection of stereo photography.

Polarization is the method currently used in digital 3-D movies as well as most stereo movies of the 1953 3-D boom.

As mentioned above, anaglyphs may also be projected.

Autostereoscopic Monitors

Based on lenticular technology, this is a more recent development of viewing 3-D imagery without the need for glasses. Autostereoscopic monitors are still in their infancy, but improvements are coming all the time for improved viewing of 3-D viewing on a TV or computer without glasses. Autostereoscopic televisions are available up to 65".

Notable Stereo Photographers

• Jacobus G. Ferwerda
• William Gruber, inventor of View-Master
• Harold Lloyd
• Christopher Scneberger
• Vladimir
• Pat Whitehouse

Links

• Stereoscopy.com
• Berezin Stereo, Stereo Photography Supplier

Glossary Terms