“Over 125 years, the global filmmaking community has been engaged in an informal science of vision, conducting a large number of trial-and-error experiments on human perception. The results are not to be found in any neuroscience or psychology textbook, though you can find some in books on cinematography and film editing, and in academic papers analysing individual films. Other insights are there in the films themselves, waiting to be described. In recent years, professional scientists have started to mine this rich, informal database, and some of what we have learned is startling.”