Jerkiness
Jerkiness describes the perception of individual still images while watching a motion picture.
Description
Motion pictures are made from still images shown in rapid sequence. Provided there is sufficient continuity between the images and provided the sequence is shown fast enough, the central nervous system interprets the sequence as continuous motion. However, some technologies cannot process or carry data fast enough for sufficiently high frame rates. For example, viewing motion pictures by Internet connection generally necessitates a greatly reduced frame rate, making jerkiness clearly apparent.In conventional cinematography, the images are filmed and displayed at 24 frames per second, at which speed jerkiness is not normally discernible. Television screens refresh at even higher frequencies. PAL and SÉCAM television refresh at 25 or 50 frames per second. NTSC television displays refresh at 29.97 frames per second.
Animated cartoon films are typically made at reduced frame rates so as to limit production costs, with the result that jerkiness tends to be apparent, especially on older limited animation features.