Topic summary
Flicker fusion
Extracted from the Wikipedia article Flicker fusion threshold.
Display frame rate
Flicker fusion is important in all technologies for showing moving images, nearly all of which depend on showing a rapid succession of static images (e.g. the frames in a cinema film, TV show, or a digital video file). If the frame rate falls below the flicker fusion threshold for the given viewing conditions, flicker will be apparent to the observer, and movements of objects on the film will appear jerky. For the purposes of displaying moving images, the human flicker fusion threshold is usually taken between 48 and 60 Hz, though in certain cases it can be higher by an order of magnitude. In practice, movies since the silent era are recorded at either 16 or 24 frames per second and projected by repeating each frame three or two times (respectively) for a flicker of 48 Hz. A television picture typically originates at 50 or 60 frames or interlaced fields per second.