Chapter 73 Two - Stroke Apparent Motion

The Effect One hundred years ago, the Gestalt psychologist Max Wertheimer published the first detailed study of the apparent visual movement seen when two adjacent lights are flashed sequentially (see Kolers, 1972). Apparent movement can be created by presenting any two identical pictures successively, with the second shifted slightly in position relative to the first. Figure 73-1a shows a very simple example: a bright bar on a dark background is plotted in cross-section, displacing to the right from frame 1 (F1) to frame 2 (F2; solid arrow). The displacement evokes a perception of apparent motion to the right (dashed arrow). Stopframe animation is based on this well-established technique.