How was the three-dimensional effect obtained in the 19th century?

Stereoscopic photography was the first three-dimensional photography in history. It developed after 1851. Then, it was demonstrated for the first time at the London World Exposition, where spatial photographs aroused the delight of Queen Victoria. From that time on, stereoscopic photography became the entertainment of the bourgeoisie, and it was not until the 1930s — when fascination with film and radio began — that stereoscopy was reduced to the role of a children’s toy. An optical instrument is used for viewing images in stereoscopy: a stereoscope. Stereoscopic photography consists of two photographs of the same object, made from different points of view. The viewer — looking through the stereoscope — gets the impression of the spatiality and three-dimensionality of the scene being viewed. Stereoscopy is one of the imaging techniques reflecting the impression of spatial vision and the depth of the image under observation. Today, stereoscopy is a 3D technique, obtaining images by reproducing the binocular visual effect, which gives the impression of depth. They are obtained by creating anaglyph paintings. The anaglyph method has gained popularity thanks to computer processing.
Stereoscopy requires the delivery of two images seen from the perspective of both the left and right eye to the brain. For this purpose, a pair of two-dimensional images (stereo pairs) are registered, representing the object or scene from two points of view, spaced as far apart from one another as the observer’s eyes. The images differ according to the angle of view of the objects concerned.
What is the history of this technique? An Italian physicist, Giambattista Della Porta (1538–1615), wrote about creating the illusion of spatial vision in 1593. His work was forgotten; it was not until 1838 that an English physicist, Sir Charles Wheatstone, built a camera for viewing spatial images and named it a stereoscope (it was a reflective stereoscope). He ordered a few pairs of photos (talbotypes) from William H. Fox Talbot. Ten years later, David Brewster improved Wheatstone’s idea. A pair of photos was made with a camera with two lenses, and it amazed everybody with its naturalistic projection of space. The photographs were presented, as already mentioned, in 1851. In 1861, the American, Oliver Wendel Holmes, constructed a light stereoscope. He did not patent his design, which spread greatly. The development of stereoscopic photography began when — in 1871 — dry glass plates with a gelatine emulsion were invented, which were sensitive and liberated photographers from the proximity to their photographic darkrooms. In the 19th century, mass-produced copies of stereoscopic images began to enter the market. Walery Rzewuski soon applied the new technique in his photographic atelier.

See also: 
The “Mercury” Stereoscope viewer by Underwood & Underwood, Stereoscopic camera by Heinrich Ernemann A.G. Company and Duchessa Stereo — stereoscopic camera by Contessa Nettel A.G. Company.

Elaborated by Małgorzata Kanikuła (Museum of Photography in Kraków), © all rights reserved