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February 15th, 2007, 08:01 AM | #121 | |
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February 15th, 2007, 04:35 PM | #122 | ||
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Below is a clarification of my previous post. Paul Wheeler says it best in his book, High Definition and 24p Cinematography, Focal Press, 2003, reprinted 2004, 2005. In his book on pages 23 and 24, he states the following: "...so the SMPTE were on the right track. The result of this recommendation is that, from the turn of the century to the coming of sound on film, the camera frame rate was set at roughly 16 frames per second. When sound recorded optically in synchronization with the picture came in 1927, the frame rate of 16 fps, or 60 feet of film per minute was too slow to make an adequate sound recording using the optical recording techniques available at the time. More film passing the sound head every second was needed to enable higher frequencies to be recorded with less background noise. By now, it was known that the flicker apparent in a film projected at 16 fps, or thereabouts, started to disappear above a projection rate of 20 fps. At 30 fps it seemed to disappear completely even on the most demanding scenes, these usually being those with pronounced highlights, as flicker is more discernible in the brighter areas of a scene. In America the mains electricity has a frequency of 60 cycles per second (cps); therefore, a standard synchronous electric motor will have a shaft speed of 1440 revolutions per minute. This gives a shaft speed of 24 revolutions per second. The Americans, who after all pioneered the making of the talkies, therefore chose the very convenient rate of 24 fps as being almost totally free of any flicker, producing a linear film speed sufficiently high to enable good sound to be recorded with the picture on the same piece of film and being absurdly simple to drive the projectors at a constant speed from a simple synchronous motor. This frame rate (24 fps) is today the world standard for theatrical motion pictures." So we owe the Film Industry's move to 24 fps film speed to the advent of talkies and our 60 hz. electrical system which delivered 24 cycles per second (1440 cycles per minute), along with simple synchronous motors in film projectors. I hope this clears things up a little, Dave. Last edited by Dave F. Nelson; February 15th, 2007 at 07:42 PM. |
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February 16th, 2007, 10:21 AM | #123 |
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Right back at ya, Dave
Scott Eyman, (1999) The Speed of Sound: Hollywood and The Talkie Revolution 1926-1930" John Hopkins University Press Page 112 I hope that muddies things up a little... |
February 16th, 2007, 01:24 PM | #124 | |||
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I appreciate the quote and the reference. You have been very helpful. Thanks, Dave. Last edited by Dave F. Nelson; February 16th, 2007 at 07:03 PM. |
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