Editing Frame rate (section)

===Silent film===
Early [[silent film]]s had stated frame rates anywhere from 16 to 24 frames per second (FPS),<ref>{{cite book |chapter-url=https://books.google.com/books?id=sWdBAQAAQBAJ&pg=PA588 |title=The Oxford Handbook of Film Music Studies |chapter=Audio-visual Palimpsests: Resynchronizing Silent Films with 'Special' Music |last=Brown |first=Julie |editor=David Neumeyer |page=588 |publisher=Oxford University Press |year=2014 |isbn=978-0195328493}}</ref> but since the cameras were hand-cranked, the rate often changed during the scene to fit the mood. Projectionists could also change the frame rate in the theater by adjusting a [[rheostat]] controlling the voltage powering the film-carrying mechanism in the [[projector]].<ref>{{cite book |title=Silent Clowns |url=https://archive.org/details/silentclowns00kerrrich |url-access=limited |last=Kerr |first=Walter |publisher=Knopf |year=1975 |page=[https://archive.org/details/silentclowns00kerrrich/page/36 36] |isbn=978-0394469072}}</ref> Film companies often intended for theaters to show their silent films at a higher frame rate than that at which they were filmed.<ref>{{cite book |title=Seductive cinema: the art of silent film |last=Card |first=James |publisher=Knopf |year=1994 |page=[https://archive.org/details/seductivecinemaa00card/page/53 53] |isbn=978-0394572185 |url-access=registration |url=https://archive.org/details/seductivecinemaa00card/page/53 }}</ref> These frame rates were enough for the sense of motion, but it was perceived as jerky motion. To minimize the perceived flicker, projectors employed dual- and triple-blade [[Movie projector shutter|shutters]], so each frame was displayed two or three times, increasing the flicker rate to 48 or 72&nbsp;hertz and reducing eye strain. [[Thomas Edison]] said that 46 frames per second was the minimum needed for the eye to perceive motion: "Anything less will strain the eye."<ref name=Brownlow>{{cite journal |last=Brownlow |first=Kevin |date=Summer 1980 |title=Silent Films: What Was the Right Speed? |journal=[[Sight & Sound]] |volume=49 |issue=3 |pages=164–167 |url=http://www.cinemaweb.com/silentfilm/bookshelf/18_kb_2.htm |archive-url=https://web.archive.org/web/20110708155615/http://www.cinemaweb.com/silentfilm/bookshelf/18_kb_2.htm |archive-date=8 July 2011 |access-date=2 May 2012}}</ref><ref>{{cite book |last1=Elsaesser |first1=Thomas |last2=Barker |first2=Adam |title=Early cinema: space, frame, narrative |year=1990 |publisher=BFI Publishing |isbn=978-0-85170-244-5 |page=284}}</ref> In the mid to late 1920s, the frame rate for silent film increased to 20–26&nbsp;FPS.<ref name=Brownlow/>