8mm Forum: 24 fps vs 25 fps

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Topic: 24 fps vs 25 fps

Melvin England
Jedi Master Film Handler

Posts: 707
From: Hull, East Yorkshire, UK
Registered: Feb 2016

posted October 19, 2017 08:07 AM

Can I firstly say that I may be completely off target with this query... but here goes....

In the "good 'ole days" when we went to the cinema and actually saw 35mm film being projected,it was at 24 frames per second. When it was shown on TV it had to run at 25fps to fit broadcasting requirements,thus losing a few minutes screen time as opposed to the cinema.
Nowadays, it is all digital. So my questions are....
1) Are digital films in the cinema now shown at 25 fps ?
2) If so, are the films actually being shot digitally,so also being made at 25 fps, OR are they being shot on celluloid at 24 or 25 fps then being transferred to the digital format?

I know a lot of you are very technical people,so I am looking forward to your replies.
Thank you.

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"My name is for my friends!"

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Maurice Leakey
Film God

Posts: 5895
From: Bristol. United Kingdom
Registered: Oct 2007

posted October 19, 2017 09:57 AM

Melvin
You may be interested in the item which I have put up below, it seems to cover many items in using HFR (High Frame Rate). I understand that cinema digital projectors actually insert "black frames" to make our eyes accustomed to the projection.
http://vanillavideo.com/blog/2012/history-frame-rates-why-speeds-vary

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Maurice

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Alexander Vandeputte
Expert Film Handler

Posts: 243
From: Belgium
Registered: Nov 2009

posted October 19, 2017 10:42 AM

Most DCP's run at 24 frames. Some movies (mostly European) that are shot on 25 frames are delivered on DCP's that play out at 25 frames.
Projectionists can't mess with the speed anymore, as the DCP dictates the speed. In the days of celluloid projection, many cinema's showed films at 25 frames. Shaving off a couple of minutes per show...

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Ty Reynolds
Film Handler

Posts: 93
From: Calgary, Alberta, Canada
Registered: Nov 2015

posted October 19, 2017 11:29 AM

In the case of NTSC (North American) television, which runs at 29.97 fps, the film speed is not altered. Instead, the five-blade shutter of the telecine projector works its magic to synchronize the film projection with the video frame rate. A 90-minute movie is still 90 minutes.

Is it not a similar case with PAL (European) broadcasting. Or is the film actually sped up to 25 fps?

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Brian Fretwell
Phenomenal Film Handler

Posts: 1785
From: London, UK
Registered: Jun 2014

posted October 19, 2017 11:47 AM

Film in the UK TV system is transmitted at 25fps. I'm sure now all film is transmitted from files and have been scanned on frame by frame telecine/datacine machines (such as the Philips/Kodak Spirit) without shutters.

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