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SDX900 vs Res Interlace

Published : 9th July 2004


Dear CML'ers

I'm shooting a pilot on the SDX 900, 16:9, 24P to be edited and on-lined on an AVID (media composer, ie edited like standard NTSC video).

Do I want the Vertical Res to be INTERLACE or PROGRESSIVE?

I understand that the typical 24 frame film to NTSC video telecine 3:2 pulldown output would be a 29.97 interlaced output, so I'm assuming that INTERLACED Vertical Res is the safe answer and that the PROG setting will require progressive editing, whatever that is.

Also, what is 24PA mode?

Thanks in advance,

Confused in Miami,

Byron Shah
DP LA



Hello Byron


>Do I want the Vertical Res to be INTERLACE or PROGRESSIVE?

Is your release to be on film or TV. If TV then INTERLACE. Why? Because it is addressing a filter for Vertical Resolution. TV has a limit of about 360 lines. Film has no problem with 480 which is what the camera would produce in PROGRESSIVE. TV on the other hand would take all of that extra resolution and make into aliased garbage, and that the PROG setting…

>will require progressive editing, whatever that is? Also, what is 24PA >mode?

You might consider extraction to 24P even if your release is 60i, just because it keeps the frame/field relationship correct and when you output again to tape reinsert the 2:3 pulldown for the 60i recording. Otherwise you will need to be constantly aware of where you are editing, and you cannot be anywhere near the two odd composite frames for fear of odd even frame relationships or potential color shifts.

2:3 24P
AA BB BC CD DD
12 12 12 12 12

Note that the C frame is now reversed if extracted in reverse order. Each NLE has a means of dealing with this and I believe the Avid keeps the BC frame and the CC frame. But I am recalling under the murky condition of a real killer cold. Get the real skinny from Avid.

The 24PA is a cool trick. In this mode there is only one composite frame and thus much easier to extract.

2:3:3:2 24PA
AA BB BC CC DD

In Standard 2:3 there are two frames that need to be messed with and it is not as clean of an extraction. The Avid Adrenaline will be able to extract either. You just have to tell it.

I hope this helps. Feel free to contact offline.

Best regards,

Jan

Jan M. Crittenden
Product Line Business Manager, DVCPRO50/25, Cameras
Panasonic Broadcast & TV Systems
One Panasonic Way, 2E-7
Secaucus, NJ 07094



Jan Crittenden wrote :

>Otherwise you will need to be constantly aware of where you are editing, >and you cannot be anywhere near the two odd composite frames for >fear of odd even frame relationships or potential color shifts.

Jan, like everyone else here I do appreciate your presence and I respect your knowledge of your products. So please don't take this the wrong way.

I think you might be taking your own company's hype a bit too seriously, because that statement is complete and utter nonsense. We've been on-lining film originated television programs for almost 20 years without regard for 3:2 cadence and it's never, ever been a problem. As for recovering constant cadence, there are at least 2 companies that specialize in doing this from "random cadence" assemblies for Fox programs that are required to be delivered with constant cadence, so that isn't a problem either.

While there is some value to editing in 24fps even if the delivery is 60i (well, mostly the ability to make a 24fps DVD), it is certainly not required and not technically necessary. And it is confusing and wrong to imply that editors must keep track of cadence for technical reasons.

Mike Most
VFX Supervisor
IATSE Local 600
Los Angeles



Michael,

So please don't take this the wrong way.

I won't, I am only reporting what I have seen happen.

>I think you might be taking your own company's hype a bit too >seriously, because that statement is complete and utter nonsense. >We've been on-lining film originated television programs for almost 20 >years without regard for 3:2 cadence and it's never, ever been a >problem.

Michael I know that you mean well, but don't take this the wrong way, it is not my company's hype that causes me to say these things. I am not a hype kind of person. I find your comments to be interesting because it now makes me wonder what these other individuals did that caused the problems that I have seen. One was a field reversal order problem and the other was a slight chroma shift. Unfortunately I will probably never know.

>As for recovering constant cadence, there are at least 2 companies that >specialize in doing this from "random cadence" assemblies for Fox >programs that are required to be delivered with constant cadence, so >that isn't a problem either.

Do you know the names of those programs/companies? The number of times I am asked these questions you cannot count, the problem is that I am not an editor, and the people that end up sharing things with me are for all intents and purpose, seemingly competent people, so something in their setup is causing a problem. So I am looking for answers that are more universally going to offer complete success.

>While there is some value to editing in 24fps even if the delivery is 60i >(well, mostly the ability to make a 24fps DVD), it is certainly not required >and not technically necessary. And it is confusing and wrong to imply >that editors must keep track of cadence for technical reasons.

But again check me if I am wrong here, if I make a 60i DVD with the footage that I have just edited with out paying attention to cadence, does that not cause me a problem when I start to do encoding to MPEG? This is another area where I have seen this come back to me as a problem.

My suggestion has been to just extract the 24P, work there and put 3:2 back in on the way out. Seems to be vastly easier these days, especially on the Apple platform.

Appreciate any insight,

Jan Crittenden



Jan Crittenden wrote :

>Do you know the names of those programs/companies? That do >constant cadence processing...

The one I remember (it's been a few years since I had to be involved in TV post production) was International Image in Santa Monica. They are an offshoot of a Canadian company that opened here specifically to do, among other things, constant cadence processing for Fox filmed shows. Hopefully they're still around, but if they're not, you could call someone at Boston Public (I'll tell you off list who to call if you're interested) and find out who they're using these days (it was International Image, but it may be someone else now).

>But again check me if I am wrong here, if I make a 60i DVD with the >footage that I have just edited with out paying attention to cadence, does >that not cause me a problem when I start to do encoding to MPEG?

That depends on the material and how you're making the DVD. DVD's are made from video edited 24p footage with changing cadence all the time (many trailers, making-ofs, deleted scenes). If the DVD is being encoded professionally, the pulldown can be changed on a cut by cut basis, so the problem ceases to exist. If you're using a PC or a Mac to manufacture the DVD, I guess you might run into a problem, although to be honest, I've done compression using the Sorenson Squeeze software and specifying Reverse Telecine on Evens, and it properly removed the pulldown on a shot by shot basis on 2 scenes from a television program (about 3 minutes per scene, numerous cuts, 3:2 pulldown throughout, no attention to cadence) without a hitch. And I've NEVER had a problem when making a 60i DVD regardless of the source.

>My suggestion has been to just extract the 24P, work there and put 3:2 >back in on the way out. Seems to be vastly easier these days, >especially on the Apple platform.

Yes, but only if you have a Mac that's fast enough to do 3:2 pulldown in real time for viewing and video out. That would eliminate anything less than a dual 1 GHz G4, and it eliminates all PowerBooks. It also eliminates anyone using Avid Xpress Pro unless they have the Avid Mojo. Since many users cut on PowerBooks, I would ask that question before giving this advice. Not to mention that this only holds true if you're using 24p Advanced for ingestion in real time on either platform (you've got to go into Cinema Tools to remove "standard" 3:2).

My advice continues to be to cut at 29.97 if you're shooting with standard pulldown and have no plans to record to film, and thus have used the DVX or SDX camera purely to achieve a filmic look. However, it continues to amuse me that people (not you) have so little understanding of the entire issue, and continue to have a total misunderstanding of what the DVX and SDX do, the tape format they record on, and how they do it.

Mike Most
VFX Supervisor
IATSE Local 600
Los Angeles



It continues to amuse me that people (not you) have so little understanding of the entire issue, and continue to have a total misunderstanding of what the DVX and SDX do, the tape format they record on, and how they do it.

Easily the most misunderstood concept in video today. I'm constantly explaining it to people, and most of them should really know better.

Mitch Gross
NYC DP



Michael Most wrote :

>Yes, but only if you have a Mac that's fast enough to do 3:2 pulldown in >real time for viewing and video out. That would eliminate anything less >than a dual 1 GHz G4, and it eliminates all PowerBooks.

Not true, we used a PowerBook at DV expo for the DV50 timeline off the internal drive.

>It also eliminates anyone using Avid Xpress Pro unless they have the >Avid Mojo. Since many users cut on PowerBooks, I would ask that >question before giving this advice.

Actually with the Avid product that only handles the DV25 at this time and you are right the Mojo is required. The Apple Processor has to be only 800mhz to do the real time 3:2.

>continues to amuse me that people (not you) have so little >understanding of the entire issue, and continue to have a total >misunderstanding of what the DVX and SDX do, the tape format they >record on, and how they do it.

This doesn't surprise me at all. Since we are the only manufacturers that are doing it and it has only been delivering since October 2002, in the case of the DVX and June 2003 for the SDX. it is out of the box thinking. Additionally, people, adult learners, never learn something new until they need to. So with a new technology, it is off their radar until it becomes important or meaningful. I have gotten it down to the back of a business card in a quick impromptu 2:3, 2:3:3:2 pulldown lesson, but I give away at least a couple dozen business cards at every show.

Thanks,

Jan Crittenden



Jan Crittenden wrote :

>The Apple Processor has to be only 800mhz to do the real time 3:2.

Is that what Apple claims? Are you sure they don't mean DUAL 800MHz?? Because I've got a Titanium 1GHz PowerBook, and no matter what I do, it only allows 2:2:2:4 playback, regardless of whether I'm using DV, Offline RT, internal drive, or Firewire drive. And regardless of how few tracks are on the timeline. All other selections are greyed out. And that's also the case with anyone else I've ever talked to who's using a PowerBook, Titanium or Aluminium.

I've also asked a number of Apple reps who confirmed the same thing. If there's something you know that I don't about how to access those functions, please post it here because I and anyone else I know with a PowerBook would like to hear it. I'd also like to know exactly what PowerBook model was able to play out DV50 source with real time 3:2 insertion, because there's no PowerBook I've ever seen that does that.

The only way I have ever been able to get 24p material to play back correctly (i.e., with 3:2 pulldown inserted) has been to encode to MPEG2 using Compressor's film setting, and burning the DVD using DVD Studio Pro (you can't do this with iDVD because it will only accept QuickTime files).

Although I've been told that exporting to a 29.97 QuickTime file also works, it never has for me - it always inserts what is essentially a 2:2:2:4 pulldown, producing unacceptable stutter. I guess you could export a QTReference movie and process the whole thing in After Effects, but that is not a useful scenario.

Jan Crittenden wrote :

>This doesn't surprise me at all. Since we are the only manufacturers >that are doing it and it has only been delivering since October 2002, in >the case of the DVX and June 2003 for the SDX. it is out of the box >thinking.

Was the Varicam released prior to that? It seems that most people don't understand the recording system on that product either, which is interesting in light of the similarity in the DVX/SDX approach (with frames instead of fields, of course...).

Mike Most
VFX Supervisor
IATSE Local 600
Los Angeles



>I'm shooting a pilot on the SDX 900, 16:9, 24P to be edited and on-lined >on an AVID (media composer, ie edited like standard NTSC video).

>Do I want the Vertical Res to be INTERLACE or PROGRESSIVE?

INTERLACE is like THICK on the DVX100A: It more-or-less smears vertical detail across two scan lines to avoid 30 Hz twitter on thin horizontal lines. Most SDTV cameras these days quote a vertical res of 400 TV lines with interlaced, dual-row readout, and my experience with THICK mode on the DVX100/100A leads me to believe that that would be the rough value on the SDX900 (though I've only played with that camera
briefly).

PROGRESSIVE does no vertical smoothing and should give you 480 TV lines vertical resolution. You'll get more twitter.

The choice here is a trade off between detail and twitter and will not impact / is not impacted by the fact that you're editing at 60i. But if your output is for 60i NTSC, not for standard conversion, film out or upconversion, INTERLACE is probably the best bet.

> Also, what is 24PA mode?

Details at http://www.adamwilt.com/24p/index.html#24pRecording

Adam Wilt / Video Geek / Menlo Park CA USA



Michael Most said :

Are you sure they don't mean DUAL 800MHz??

You are right here, Sorry. I just re-read the note from the Apple guys.

>Because I've got a Titanium 1GHz PowerBook, and no matter what I do, >it only allows 2:2:2:4 playback

Not that I would know the Titanium from the Aluminium, I know we had the 17" 1GHz laptop at DV Expo LA and we were running a standard 2:3 pulldown with internal drives. I just confirmed this with our editor that was there. Now the 17" Laptop may not be considered a PowerBook, I don't know. I only know that this is what we had and it worked extremely well.

Best regards,

Jan Crittenden



Jan Crittenden wrote :

>Not that I would know the Titanium from the Aluminium, I know we had >the 17" 1GHz laptop at DV Expo LA and we were running a standard 2:3 >pulldown with internal drives. I just confirmed this with our editor that >was there.

I think it's probably time to end this. My only point was that blanket advice that claims it's "easy" to use 24pA through a post path if you're cutting on a Mac with Final Cut is probably misleading to a lot of Final Cut users. Not everyone uses dual proc desktop Macs, and a lot of those using PowerBooks aren't using the ones that were only introduced 3 months ago - if those can actually do the pulldown in the first place (I still doubt it).

One of the great attractions of Final Cut to a lot - and I mean a lot - of editors and those who need to be on occasion is the fact that you can run it on a laptop. In most if not all of those cases, the claim that you can simply play out with 3:2 pulldown inserted on the fly is just not true.

I'm just trying to avoid having other users believe the claims only to be disappointed - as I have been.

Mike Most
VFX Supervisor
IATSE Local 600
Los Angeles



>I'm shooting a pilot on the SDX 900, 16:9, 24P to be edited and on-lined >on an AVID (media composer, i.e. edited like standard NTSC video).

>Do I want the Vertical Res to be INTERLACE or PROGRESSIVE?

Adam wrote:

>INTERLACE is like THICK on the DVX100A ...

Actually I think you have it reversed. Your description of thick is correct, but the INTERLACE setting on the SDX900 is like thin on the DVX100. If you want the THICK setting tune you 900 to PROGRESSIVE V. DETAIL.

The test I've been involved in with Plaster City and some clients at Moviola haven't determined much of a visual difference unless you're upconverting to HD or doing a film-out. Panasonic recommends PROGRESSIVE V Res for HD upconvert and film-out, and INTERLACE V Res for all projects living in SD.

Illya Friedman
Senior Camera Rental Agent
Moviola Cameras
Hollywood, CA
www.moviola.com