What is 24p? at DVinfo.net

Stewart McDonald · June 19th, 2003, 02:57 AM

Is it 24 frames per second? And if so, why is it so important? Can't films stay at their 29.9 fps to look good?
Any info would be great.

Thanks

Frank Granovski · June 19th, 2003, 03:17 AM

Film plays at 24fps. But when shooting film, the speeds vary: higher speed capture for slow motion, lower speed capture for fast motion. 29.97fps is the NTSC broadcast frame rate---but the frames are split in half as odd and even fields. PAL, SECAM and MESECAM are 50 fields per second, except for Brazil---more or less.

Cazi Brasga · June 20th, 2003, 10:47 AM

24p stands for 24 'P'rogressive (FULL) Frames Per Second
Whereas something such as 60i would be 60 'I'nterlaced frames per sec.

Martin Munthe · June 21st, 2003, 06:31 AM

Stewart. You're in the UK. Either Film nor Video is 29,97fps where you're at. It's 25fps in video and shot 25fps on film (but projected 24fps). We all work in 25p in Europe :)

Eivind Vaa · June 22nd, 2003, 05:35 PM

Maybe somewhat off subject, but I had a discussion recently on how film is projected so that there won´t be any flickering since it´s coming at 24 frames per second. I´ve heard that each frame is projected twice, but I´m not quite sure if that´s how they do it. Anyone?

Dennis Adams · June 23rd, 2003, 08:29 PM

<<<-- Originally posted by Martin Munthe : We all work in 25p in Europe :) -->>>

Not true. Most of you across the pond work with 50i. Big difference from 25p. Only those using "frame mode" on their XL1 or the DVX100 in 25p mode are working in 25p.

Also, while 25p might look a lot like 24p, it is tricky doing a film transfer from 25p to 24p -- that's a 4% difference, which requires audio pitching and your feature runs a few minutes extra compared to the video version.

///d@

Rob Lohman · July 11th, 2003, 05:34 AM

I think Martin was referring to FILM here.... If I'm not mistaken
that is SHOT and PROJECTED at 25p in Europe.

Martin Munthe · July 11th, 2003, 07:29 AM

Rob. It's actually shot and edited in 25 But it's projected 24 (most older projectors can only project 24).

And yes; I'm aware that Europe is 50i.

Alex Dunn · July 15th, 2003, 08:48 AM

50i = 25p

Martin is correct. It's pretty well known that voices in European films are heard a fraction of an octive higher due the the 1 fps accelleration. It is considered a waste of time to convert the format from 25fps (50i) to 24fps for projection.

My only question is, why don't they just modify the projector???
(This is a redundant question the does not warrant an answer)

Rob Lohman · July 16th, 2003, 03:25 AM

Well, 50 fields per second is 25 frames per second. But it isn't
the same due to time difference in the fields.

Dennis Adams · July 16th, 2003, 07:05 AM

People are always claiming that film is shot and/or edited at 25 fps in Europe, but I've yet to find a verifiable source of this informaiton. I contend that it is not. It is shot and edited at 24 fps just like the rest of the world. The only time 25 fps comes into play is during a PAL tranfer, where it is sped up 4% and the audio re-pitched accordingly (I'm well aware of the process, we used to have a division that did format conversions). If you want to argue about it, provide some legitimate sources.
///d@

Alex Dunn · July 16th, 2003, 08:44 AM

Oops, that's what I meant. I said it backwards. Sorry!! I was also not aware of the audio re-pitch, I have always heard they don't bother.

June 19th, 2003, 02:57 AM	#1
Stewart McDonald Regular Crew Join Date: Feb 2003 Location: UK Posts: 130	What is 24p? Is it 24 frames per second? And if so, why is it so important? Can't films stay at their 29.9 fps to look good? Any info would be great. Thanks

June 21st, 2003, 06:31 AM	#4
Martin Munthe Major Player Join Date: Apr 2002 Location: Stockholm, Sweden Posts: 331	Stewart. You're in the UK. Either Film nor Video is 29,97fps where you're at. It's 25fps in video and shot 25fps on film (but projected 24fps). We all work in 25p in Europe :) __________________ Martin Munthe VFX Supervisor/DP/Director

June 22nd, 2003, 05:35 PM	#5
Eivind Vaa Regular Crew Join Date: Apr 2003 Location: Norway Posts: 35	Maybe somewhat off subject, but I had a discussion recently on how film is projected so that there won´t be any flickering since it´s coming at 24 frames per second. I´ve heard that each frame is projected twice, but I´m not quite sure if that´s how they do it. Anyone? __________________ Eivind Vaa

July 11th, 2003, 05:34 AM	#7
Rob Lohman RED Code Chef Join Date: Oct 2001 Location: Holland Posts: 12,514	I think Martin was referring to FILM here.... If I'm not mistaken that is SHOT and PROJECTED at 25p in Europe. __________________ Rob Lohman, visuar@iname.com DV Info Wrangler & RED Code Chef Join the DV Challenge \| Lady X Search DVinfo.net for quick answers \| Buy from the best: DVinfo.net sponsors

July 11th, 2003, 07:29 AM	#8
Martin Munthe Major Player Join Date: Apr 2002 Location: Stockholm, Sweden Posts: 331	Rob. It's actually shot and edited in 25 But it's projected 24 (most older projectors can only project 24). And yes; I'm aware that Europe is 50i. __________________ Martin Munthe VFX Supervisor/DP/Director

June 19th, 2003, 03:17 AM	#2
Frank Granovski Outer Circle Join Date: May 2002 Location: Hope, BC Posts: 7,524	Film plays at 24fps. But when shooting film, the speeds vary: higher speed capture for slow motion, lower speed capture for fast motion. 29.97fps is the NTSC broadcast frame rate---but the frames are split in half as odd and even fields. PAL, SECAM and MESECAM are 50 fields per second, except for Brazil---more or less.

June 20th, 2003, 10:47 AM	#3
Cazi Brasga New Boot Join Date: May 2003 Location: Temecula, CA Posts: 5	24p stands for 24 'P'rogressive (FULL) Frames Per Second Whereas something such as 60i would be 60 'I'nterlaced frames per sec.

June 23rd, 2003, 08:29 PM	#6
Dennis Adams Regular Crew Join Date: May 2003 Location: Madison, WI Posts: 123	<<<-- Originally posted by Martin Munthe : We all work in 25p in Europe :) -->>> Not true. Most of you across the pond work with 50i. Big difference from 25p. Only those using "frame mode" on their XL1 or the DVX100 in 25p mode are working in 25p. Also, while 25p might look a lot like 24p, it is tricky doing a film transfer from 25p to 24p -- that's a 4% difference, which requires audio pitching and your feature runs a few minutes extra compared to the video version. ///d@

July 15th, 2003, 08:48 AM	#9
Alex Dunn Major Player Join Date: Aug 2002 Location: Phoenix, AZ Posts: 202	50i = 25p Martin is correct. It's pretty well known that voices in European films are heard a fraction of an octive higher due the the 1 fps accelleration. It is considered a waste of time to convert the format from 25fps (50i) to 24fps for projection. My only question is, why don't they just modify the projector??? (This is a redundant question the does not warrant an answer)

July 16th, 2003, 03:25 AM	#10
Rob Lohman RED Code Chef Join Date: Oct 2001 Location: Holland Posts: 12,514	Well, 50 fields per second is 25 frames per second. But it isn't the same due to time difference in the fields. __________________ Rob Lohman, visuar@iname.com DV Info Wrangler & RED Code Chef Join the DV Challenge \| Lady X Search DVinfo.net for quick answers \| Buy from the best: DVinfo.net sponsors

July 16th, 2003, 07:05 AM	#11
Dennis Adams Regular Crew Join Date: May 2003 Location: Madison, WI Posts: 123	People are always claiming that film is shot and/or edited at 25 fps in Europe, but I've yet to find a verifiable source of this informaiton. I contend that it is not. It is shot and edited at 24 fps just like the rest of the world. The only time 25 fps comes into play is during a PAL tranfer, where it is sped up 4% and the audio re-pitched accordingly (I'm well aware of the process, we used to have a division that did format conversions). If you want to argue about it, provide some legitimate sources. ///d@

July 16th, 2003, 08:44 AM	#12
Alex Dunn Major Player Join Date: Aug 2002 Location: Phoenix, AZ Posts: 202	Oops, that's what I meant. I said it backwards. Sorry!! I was also not aware of the audio re-pitch, I have always heard they don't bother.