Editing Frame rate (section)

===Modern video standards===
{{See also|List of broadcast video formats}}
Due to the [[mains frequency]] of electric grids, analog television broadcast was developed with frame rates of 50&nbsp;Hz (most of the world) or 60&nbsp;Hz (Canada, US, Mexico, Philippines, Japan, South Korea). The frequency of the electricity grid was extremely stable and therefore it was logical to use for synchronization.

The introduction of color television technology made it necessary to lower that 60&nbsp;FPS frequency by 0.1% to avoid "[[dot crawl]]", a display artifact appearing on legacy black-and-white displays, showing up on highly-color-saturated surfaces. It was found that by lowering the frame rate by 0.1%, the undesirable effect was minimized.

{{As of|2021}}, video transmission standards in North America, Japan, and South Korea are still based on 60/1.001&nbsp;≈&nbsp;59.94 images per second. Two sizes of images are typically used: 1920×1080 ("1080i/p") and 1280×720 ("720p"). Confusingly, ''interlaced'' formats are customarily stated at 1/2 their image rate, 29.97/25&nbsp;FPS, and ''double'' their image height, but these statements are purely custom; in each format, 60 images per second are produced. A resolution of 1080i produces 59.94 or 50 1920×540 images, each squashed to half-height in the photographic process and stretched back to fill the screen on playback in a television set. The 720p format produces 59.94/50 or 29.97/25 1280×720p images, not squeezed, so that no expansion or squeezing of the image is necessary. This confusion was industry-wide in the early days of digital video software, with much software being written incorrectly, the developers believing that only 29.97 images were expected each second, which was incorrect. While it was true that each picture element was polled and sent only 29.97 times per second, the pixel location immediately below that one was polled 1/60 of a second later, part of a completely separate image for the next 1/60-second frame.

At its native 24&nbsp;FPS rate, film could not be displayed on 60&nbsp;Hz video without the necessary [[Three-two pull down|pulldown]] process, often leading to "[[judder]]": to convert 24 frames per second into 60 frames per second, every odd frame is repeated, playing twice, while every even frame is tripled. This creates uneven motion, appearing stroboscopic. Other conversions have similar uneven frame doubling. Newer video standards support 120, 240, or 300 frames per second, so frames can be evenly sampled for standard frame rates such as 24, 48 and 60 FPS film or 25, 30, 50 or 60 FPS video. Of course these higher frame rates may also be displayed at their native rates.<ref>[http://downloads.bbc.co.uk/rd/pubs/whp/whp-pdf-files/WHP169.pdf High Frame-Rate Television], BBC White Paper WHP 169, September 2008, M. Armstrong, D. Flynn, M. Hammond, PAWAN Jahajpuria S. Jolly, R. Salmon.</ref><ref>{{citation |url=https://www.engadget.com/2014/11/27/avatar-sequels-to-shoot-at-48fps/ |title=James Cameron's 'Avatar' sequels will stick to 48 frames per second |author=Jon Fingas |date=November 27, 2014 |work=[[Engadget]] |access-date=April 15, 2017}}</ref>