sentences:  When properly balanced (tuned) and displayed, the discrete parallax differences are perceived by the brain as depth.A continuously moving parallax scan records a pattern of sequential parallax views on a single strip of film or video tape.The lens's optical axis sweeps in the plane of the nominal X and Y axes around the nominal optical Z axis, pivoting on the optical convergence point (out along the Z axis), so that it passes through positions having parallax in relation to the optical convergence point.