Elements of Realspace Imaging: A Proposed Taxonomy

"Stereoscopic images represent two single points of view, one for each eye, separated to give a noticable lateral displacement, or parallax. Parallax is often erroneously pitched as all that is necessary for depth in imagery (the stereoscopic movies of the 1950s were simply labelled "3D"). There is no easy way to record and reproduce parallax. First, two simultaneous views must be recorded, with care taken for proper convergence and disparity. Then, each view must be seen exclusively by each eye. Stereoscopic photography has a lively history dating back at least to Wheatstone's invention of the stereoscope in 1833.6 The most popular techniques require glasses to be worn (such as anaglyphic, polarized, or shutter). Methods not requiring glasses usually require the head to be held in a particular position (using mirrors, peepholes, or lenticular screens, for example)."