Lex Luthor wrote:
Obviously higher frame-rates look progressively more real, although it reaches an asymptote at some point. My guess is that 24 was used because it's easy to divide 24 by other numbers to cut up the film... for example 6 frames is exactly 1/4 of a second, 4 frames 1/6, etc.
Actually, the original film "standard" (as there was no standard) was around 16 frames per second, which was the average number of frames shot by the camera man working with a hand cranked camera. Obviously, there is variation here depending on cameraman, but in general that was close.
Quote:
In 1925, director Al Rogell wrote in Director magazine: 'At a recent meeting, the Society of Motion Picture Engineers advocated a universal set speed for projection of 80 feet per minute (21.3 frames per second). As a matter of fact, most theatres show pictures at a speed of 85-90 ft. per minute (22.6 fps - 24 fps) in these days of long shows with 10-11 reels of film and various entertainment acts.'
That same year (1925) the head of a theatre chain in Indiana claimed that 24 fps was now the standard speed. Again the cameramen denied it. Paul Perry, in the American Cinematographer, claimed that he had checked with his colleagues and found the majority cranking at- you've guessed it- 16 fps, 60 feet per minute. The Polygon may not be a definitive scientific instrument, but no film of 1925 we put through had been shot at 16 fps. Yet Perry let slip a hint that cameramen had been asked to turn faster 'If the theatres insist on faster projection, it is only natural that some of the producers request that their film be exposed more rapidly to offset the increased speed of projection.'
Karl Malkames, the son of silent era cameraman Don Malkames, and a cameraman himself, wrote to me recently- 'The practice of cranking from 20 to 24 to compensate for rising theatrical projection speeds was common while my father was at Fox in 1924. Bell and Howell equipment continued to reflect the idea of 16 fps as "normal". The shutter speed plate on my later model Bell and Howell, circa 1930, is still calibrated for 16 fps.'
The Bell and Howell 2709 camera became the standard studio model of the 1920s. Two turns of the handle sent one foot of film through the gate- one foot of film contained sixteen frames of picture, so two turns per second equalled sixteen frames, the 'standard' speed. Cameramen prided themselves on their even rate of cranking. To achieve it, you said 'One hundred and one' to yourself, over and over, until the speed came naturally. One cameraman blamed the 'Anvil Chorus' from II Trovatore. While the speed was undoubtedly even, how could they know precisely what their speed was? Could they honestly say they were cranking at 16 and not 18 frames per second? For there was no speed indicator on the Bell and Howell.
Kemp Niver has interviewed a number of silent-era cameramen for the American Society of Cinematographers. 'To a man, they said that unless there was some specific reason... they tried to maintain 16 fps. No cameraman could make a statement that he cranked at a specific speed and prove it unless he had a stop watch at the start and end of a given number of feet of film. Even then he couldn't guarantee that he wasn't undercranking or over-cranking as the tension on the take-up magazine increased.'
A motor was available for the Bell and Howell, with a speed indicator. Predictably, 16 fps is marked NORMAL. The top speed is 22 fps. In production stills, this motor appears more and more often towards the end of the 20s. In the old days, they said they preferred hand cranking. So why the motor? Perhaps because of the increased demands of the mobile camera- now far more common- which needed more manipulation than the static camera. And perhaps because a standard speed had at last arrived. In October 1927 The Jazz Singer had been premiered, and theatres were being wired for sound. The standard speed of sound films was 24 fps. It is interesting to discover how that speed was arrived at.
According to Stanley Watkins, head engineer for Western Electric, he and his team checked with the Warner Theatre for the average speed of projection in 1926. They were told 'between eighty and ninety feet per minute' in the big theatres- between 20 and 24 fps- and around 26 fps in the smaller theatres. They settled on 90 feet a minute (24 fps) as a reasonable compromise for the Vitaphone process.[2] The other sound systems began at slower speeds (Fox-Case's first tests were shot at 21 fps), but they, too, adopted 24 fps as standard in November 1926.
If Hollywood cameramen were still working rigidly at 16 fps, their work would have looked ludicrous in the public theatres. The fact that they were cranking the films slower than they were projected is borne out by The Jazz Singer. Al Jolson walks to the stage at a slightly accelerated pace, and when the Vitaphone section begins, he is filmed at 24 fps. Filmgoers often remarked that the early talkies seemed leaden-footed.
While filming Annapolis in 1928, cameraman Arthur Miller received a wire from the studio to crank at 24 fps. He did so, and everyone complained that the speed slowed everything down too much- it was particularly noticeable in a dress parade scene of midshipmen.
Walter Kerr, in his brilliant book 'The Silent Clowns,' puts forward his theory: silent films were photographed at 16 or 18 frames a second, but projected at a rate closer to sound speed. 'The result was not only faster than life, it was cleaner, less effortful, more dynamic.' Kerr illustrates his theory with a photograph of the instructions printed on the leader for the 1922 Down to the Sea in Ships: 'Operator: please run eleven minutes for 1,000 ft.'- or 24 fps, the speed of sound. I have projected the film, and found two or three sections too fast at that speed (although the remainder is satisfactory). But that was how audiences saw it at the time. Other, later films, such as The Winning of Barbara Worth, were shot at a speed so close to 24 fps that they are wrecked by being shown at 16 fps. I have even seen an occasional silent, such as The Blood Ship (1928) apparently designed to be projected at 26 fps, since sound speed is too slow for them. (Poverty Row producers like Columbia, who made The Blood Ship, ordered cameras to be cranked faster to fill their reels more economically!)
Talking about comedies, Walter Kerr writes: 'Silent films chose, by control of the camera and through instructions to projectionists, to move at an unreal, stylised, in effect fantasised rate.' And he quotes as examples the last two silent Chaplins- both films designed to be shown at sound speed, but photographed at silent speed (whatever that was!). 'The least glance at Modern Times reveals instantly that all of Chaplin's work in the film... has been filmed at a rate that puts springs on his heels and makes unleashed jack-knives of his elbows. This is how the films looked when they were projected as their creators intended.'
[2] One reason for world standards accepting 24 fps was that it permitted flickerless projection with a 2-blade shutter. (H.A.V. Bulleid).
TLDNR Explanation: The original silent film speed (~16fps) was too slow for talkies. After experimenting with various speeds, 24 appeared to work the best for sound, and still kept the cost as minimal as possible (FILM STOCK IS EXPENSIVE!) Hence, every 35mm projector in the world has at least one mode that runs at 24fps, and is likely to be the standard for film until everything is 100% digital.