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Specification on shooting in 24fps.


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#1 Amit D Auti

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Posted 21 September 2015 - 03:08 PM

Why should one shoot in 24fps? Why not 22fps or 23fps
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#2 John E Clark

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Posted 21 September 2015 - 04:29 PM

Why should one shoot in 24fps? Why not 22fps or 23fps

 

24 fps was chosen when 'sync sound' was developed, and was a compromise on speed of the film transport vs. quality of sound vs quality of image vs cost of materials.

 

Since then, 24 fps has become an artistic element, while 30 fps is considered 'TV', and unartistic... then there's PAL at 25 fps...

 

In any case the 'interlaced' formatting of the video frames did have certain artifacts that were obvious on occasion. But for progressive frames @ 30 fps, it is an artistic choice, but since most theaters were setup for 24 fps, 30 fps could not really get in the door.

 

This days with projection systems that have variable frame rate capability, it is because of the TV association. There have been some films that have been distributed in 48 fps format, which allows them to be displayed at that rate, or temporally subsampled to 24 by 'dropping' ever other frame.

 

There may be other experiments on frame rates, but it seems for the forseeable future, 24 will be the dominant frame rate.


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#3 David Mullen ASC

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Posted 21 September 2015 - 04:55 PM

https://en.wikipedia...ema_Initiatives

Current projection standard is 24 fps.

 

This is from Scott Eyman's book, "The Speed of Sound":

 

 

 

The speed of the film bearing the sound track had been standardized at 90 feet a minute, 24 frames a second. Although tradition has had it that 90 feet a minute was the optimum speed for the quality of sound reproduction, the fact of the matter was that, originally, Earl Sponable and Theodore Case had been experimenting with a speed of 85 feet a minute, which appears
to have worked satisfactorily. As Sponable said, "After our affiliation with the [Fox company] this was changed to ninety feet a minute in order to use the controlled motors already worked out and used in the Vitaphone system."* The standardization, then, was not made for purposes of sound quality, but for maximum profits for Western Electric.
 
* Western Electric engineer Stanley Watkins averred that 24 frames per second for Vitaphone was not part of a capitalist plot, but a purely arbitrary decision. "According to strict laboratory procedures, we should have made exhaustive tests and calculations and six months later come up with the correct answer," he related in 1961. "What happened was that we got together with Warners' chief projectionist and asked him how fast they ran the [silent] film in theaters. He told us it went at eighty to ninety feet per minute in the best first-run houses and in the small ones anything from one hundred feet up, according to how many shows they wanted to get in during the day. After a little thought, we settled on ninety feet a minute as a reasonable compromise."
 
 
I pulled that from a discussion on Film-Tech Forum:

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#4 Bruce Greene

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Posted 22 September 2015 - 11:20 AM

a practical, but not historical reason:

DCP standard today is 24fps for theatrical distribution world wide.
TV distribution today is 30fps(60i) in the US, 25fps(50i) in much of the rest of the world.
24fps can be converted to 30fps (for tv) by adding at 3:2 pull down of duplicate frames. It plays pretty well and is what we're used to seeing on TV in the US.
24fps can be sped up to 25fps and shown on TV in the rest of the world in good quality. (and vise versa)
Shooting in 30 fps for tv works well, but converts poorly to 24 fps or 25fps for European TV.

So, the most compatible frame rate to shoot at today is 24fps, for distribution in theaters and TV world wide.
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#5 Amit D Auti

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Posted 22 September 2015 - 11:22 PM

Thank you Bruce Green.
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#6 Simon Wyss

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Posted 23 September 2015 - 02:26 AM

Vitaphone ran the film at 22 frames per second and the disc at 33⅓ revolutions per minute from the inside out.

 

24 is a versatile figure, dividable by 24, 12, 8, 6, 4, 3, 2, and 1. That’s useful for trick film work. Else it is 1½ the silent speed adopted in 1909. Let’s not forget that Dickson and Edison had shot at 46 fps, coming down to 41-40 in later years, and for example the Lathams at 12 fps with the Eidoloscope thanks to a 4-to-1 gearing ratio between shutter shaft and drive shaft. Louis Le Prince knew already in 1888 that some 20 fps would work well. Donisthorpe and Crofts shot at 10 fps in 1889. Green claimed to have run paper film at frame rates up to 50 in 1885 but there’s no proof to that. Edward Hill Amet could show Edison films with his Magniscope at 32 fps in 1894.


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