Max Wertheimer
The phi phenomenon is an optical illusion described by Wertheimer in 1912, in which the persistence of vision was exploited by the cinema film, applied by Hugo Münsterberg in 1916. This optical illusion is based in the principle  that the human eye is capable of perceiving movement from pieces of information, for example, a succession of images. In other words, from a slideshow of a group of frozen images at a certain speed of images per second, we observe constant movement.