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#1 Ken Minehan

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Posted 01 December 2008 - 03:52 AM

Hello guys. Can someone please explain to me the meaning of pulldown. What does 2:3 or 3:2 mean. Is this something that can only be done in telecine?
I'm in a PAL country, and a client asked for true HD (this i understand), with 24p pulldown (this is the part i dont get)
thanks
Ken Minehan
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#2 Phil Rhodes

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Posted 01 December 2008 - 04:23 AM

The request does not make sense, or at least, it's not complete in the terms you've stated it.

3:2 pulldown is a way of making 24-frame (or very nearly 24-frame) pictures work inside a 30-frame (or nearly 30-frame) video stream. The wikipedia article explains it better than I can without visual aids.

It sounds like what they might be asking for is a production shot at 24-frame (or 23.98) but delivered at 30 (or 29.97), but it's dangerous to try and do detective work in these cases. Ask them to be more specific.

P
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#3 Ken Minehan

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Posted 01 December 2008 - 05:13 AM

Thanks Phil for your explanation. The article you attached is exactly what i was looking for.
For me to convert 24frames to 25 frames so that i can broadcast in a PAL country, will i need to go through telecine? Or is pulldown something i can do in FCP?
thanks
Ken
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#4 Jim Hyslop

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Posted 02 December 2008 - 12:18 AM

For me to convert 24frames to 25 frames so that i can broadcast in a PAL country, will i need to go through telecine? Or is pulldown something i can do in FCP?

FCP can export a PAL video from an NTSC timeline. Go to File | Export | Quick Time Movie...| and change the "Setting" drop-list to one of the PAL codecs.

BTW, conversion not only changes the frame rate but the image size - PAL aspect ratio is different from NTSC.

Ah, I love standards - so many to choose from! :D

--
Jim
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#5 John Brawley

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Posted 02 December 2008 - 01:06 AM

Hello guys. Can someone please explain to me the meaning of pulldown. What does 2:3 or 3:2 mean. Is this something that can only be done in telecine?
I'm in a PAL country, and a client asked for true HD (this i understand), with 24p pulldown (this is the part i dont get)
thanks
Ken Minehan


The short answer is you don't need to worry about it if you deliver to 24 FPS. 3:2 is the technique used to convert 24 FPS to 30FPS environments. IN a PAL environment (really 25 FPS environment) then it's just sped up 4% on playback.

So, a 24 FPS master works in both 25 FPS and 30 FPS (via 3:2 pulldown) environments.

A HDCAM deck can playback a 24FPS master at 25 OR 30 fps. You don't even have to do the conversions yourself.

The p part of 24p might be what's getting you confused. It doesn't stand for pull-down, it stands for progressive.

jb
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#6 John Sprung

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Posted 03 December 2008 - 01:55 PM

For me to convert 24frames to 25 frames so that i can broadcast in a PAL country, will i need to go through telecine? Or is pulldown something i can do in FCP?

However you do it, what you need to do is run the show 4% fast, and merely take every frame straight across. We had a show once that tried to do a 3:2 style conversion, inserting extra copies of a frame twice per second to make 50i. The effect was grossly obvious. You could sit there and tap your foot to the rhythm of the motion artifacts.

The issue your client needs to consider is whether it's necessary to deal with the reduced run time, and if so, how to do it. You may end up cutting a special version, stretching things here and there.




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