best way to process 24P footage

Jason McKelvey · October 11, 2004

Hey, me again. Our footage eventually ends up on broadcast TV. So, I've been shooting in Standard 24P, V. Res on INTERLACE. In post, should this footage be deinterlaced? Sorry for the 1st grade question... I'm not much into post. Just want it to look it's best.

Sincerely,

Alvin Pingol · October 11, 2004

Not deinterlace, but rather Inverse Telecine.

I don't know how the footage from the SDX is stored on tape, but...

a) if 24P, 24fps, you don't need to do anything to it

b) 3:2:3:2 30fps, run an inverse telecine over it to remove pattern

c) 3:2:2:3 30fps, a special pattern removal is needed (standard inverse telecine wont work).

Depending on what NLE you are using, some can do b) and c) automatically, on the fly, as you import.

BTW, I forgot: You mentioned it will end up on broadcast. This means that when your master has been finished, it will be 24P/24fps. You must now have the footage put back into 60i/30fps by means of adding 3:2 pulldown so it can be played on a regular NTSC set.

Edited October 11, 2004 by Alvin Pingol

Jason McKelvey · October 12, 2004

Sooo, it wouldn't make sense to deinterlace it if you have to interlace it (3:2 pulldown) later. The footage is recorded to tape with a 3:2 pulldown in the camera so that I can play the footage right out of the camera on a regular NTSC monitor, or import it to a NLE for that matter.

Thanks,

Jason

Phil Rhodes · October 12, 2004

Hi,

> Sooo, it wouldn't make sense to deinterlace it if you have to interlace it (3:2

> pulldown) later.

Well you're not deinterlacing it, you're undoing the 3:2 pulldown which is a non-lossy process. And yes, there are reasons for doing that.

First reason is that if you cut your 3:2 material you will inevitably upset the pulldown cadence. This means that at each cut, you'll change where you are in the pulldown cadence. This makes it very difficult (practically impossible) to get to a true 24p stream if you ever need one for internet or DVD delivery (very likely) or a filmout (less likely).

The second reason is that if you do any animated graphics in the NLE, including rolling titles and dissolves, they will be rendered interlaced. This doesn't make that much difference technically if you never need a 24p stream (and you do), but it's very obvious when this is done. It's a particular pet hate of mind to see interlaced titles over 24p material; it looks like a cheap TV movie.

Phil

Alvin Pingol · October 12, 2004

It's a particular pet hate of mind to see interlaced titles over 24p material; it looks like a cheap TV movie.
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It's probably less noticeable over there in PAL-land... To see 60i titles (and even 60i fades!) over 3:2 material is just plain ugly, but I'm sure only 1% of audiences can tell.

Phil Rhodes · October 12, 2004

Hi,

Oh, it's noticeable. On the other hand I do often end up sitting looking at it all day.

Anecdotally:

On one recent project which had horizontally-scrolling text in a bar at the bottom, I actually rendered out two versions of it - one interlaced for DVD, and one noninterlaced for Quicktime on CD-ROM. The QT looked awful with the deinterlaced text if I gave it interlaced, the PAL juddered unreadably if fed progressive text. This stuff does matter.

Phil

Jason McKelvey · October 13, 2004

I'm confused now. If I have 24P (not 24PA) footage that will end up for broadcast and maybe a DVD later, I should do what? Bear in mind that this 24P footage is a small part of a program that is mainly 60i. So my time line is mostly 60i. Is there a difference between deinterlacing and a reverse 3:2 pulldown? What about 30P material... doesn't need a reverse 3:2 pulldown, but does the SDX900 deliver true progressive footage when captured to the NLE? Ugh.

Sorry for the lack of understanding,

John Morrison · October 14, 2004

Hey man, don't feel bad this is a brave new world for me as well, My buddy/colleague hates the way the 24p looks when we play it back 30fps. His issue is mostly with the motion and "judder" i believe they call it . It could be that we need to change the way we shoot and be less newsy and more cinematic, more dollys less pans. We've already had to really look at the way we light stuff, because the video "light it flat" looks like nothing in 24p land. So remember the only stupid question is the one not asked

dougcall · October 14, 2004

If your going to be targeting all the output to broadcast TV anyway why not shoot it all in 60i to start with. Then you wouldn't need to worry about all the conversions back and forth. Are you shooting it native 16:9 or 4:3?

Jason McKelvey · October 15, 2004

I don't want to shoot 60i for the same reason that 90% of TV film dramas are shot in 24P instead of 30P... the temporal asthetics 24P - even after a 3:2 - gives you. We shoot the 24P stuff in true 16:9 to mimic more of a cinematic look. Look, I know I know... 24P video won't compete with 35mm film. But I'll put my SDX900 24P 50mbs 16:9 footage up against ANY standard definition 60i footage (and some HD stuff) and on a dramatic story telling level, mine will when every time... unless you are trying to look like a reality show... then I'll lose. I have had to adjust my style of shooting as far as pan and tilt speeds. But I knew this before I ever got the camera from doing research and finding out that there are ASC charts for maximum pans at certain focal lengths. I just need to know the best way to import, edit and output my 24P footage.

Hey man, don't feel bad this is a brave new world for me as well, My buddy/colleague hates the way the 24p looks when we play it back 30fps

I hear this a lot. So I guess every cinematographer in the world has a progressive scan DVD player and a progressive scan display so they don't have to watch movies at home through a 3:2 pulldown... not to mention most prime time dramas.

Jan Crittenden · October 18, 2004

I just need to know the best way to import, edit and output my 24P footage.

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Hi Jason,

If this footage is going to mix in with other 60i footage then just import and edit, no need to extract at all. Be aware of where your edits are so they are not on the cusp of a combination frame, i.e., the BC or CD frame. These will look odd.

Hope this helps,

Jan