Stereoscopy integrates the spatial depth, the spatial perception, into photography. The spatial perception arises by viewing the space with both eyes and our brain perceives the seen as spatial depth.
We see stereo due to the eye’s distance: they have lightly different viewing positions (disparity): the lines of sight converge on the object in a differing angle (parallax). Our brain combines this to spatial perception.
For getting depth into 3d-photography (stereoscopy), it therefor needs two pictures (stereogram, left and right stereo picture) captured from lightly different positions (stereo base).
Stereoscopic camera equipment with 2 cameras on a stereo bar
When viewing stereograms, it has to be guaranteed that the left stereo picture is seen by the left eye and the right picture by the right eye.
One method for presenting stereograms is the anaglyph-method, which also is useable for printing stereograms. In the following the RED-CYAN colour combination is used. Other colour combinations are also used in applications.
Hereby, the left picture is printed in cyan and the right picture in red. When viewing such an anaglyph image with red-cyan-anaglyph-glasses, the other sided pictures are filtered out. Due to the colour filters of the anaglyph methods, no true colours are possible.
last update: 26.04.2016