The experimental origins of cinema, stereo and their combination

The rapid growth in stereoscopic cinema and television might suggest a recent concern with adding stereo depth to apparent motion, but this is not the case. Attempts were carried out by the pioneers of research on stereoscopic vision and apparent motion in the early nineteenth century. This was possible because of the instruments they invented to simulate motion and depth – phenakistiscopes (or stroboscopic discs) and stereoscopes. Sequences of still images could appear to move and paired pictures (with small horizontal disparities and presented to different eyes) were seen in depth. Subsequently, many varieties of stroboscopic discs and stereoscopes were devised and their popularity increased enormously after 1840, when combined with photography. Thereafter, sequences of stereoscopic photographs were presented in instruments called bioscopes or fantascopic stereoscopes so that the apparent motion appeared in depth. Unlike the simulation of motion and depth alone, their combination proved more difficult to achieve.