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DVX-100 24p Digitising

Published : 3rd July 2004


I've recently heard about people having odd experiences when digitizing Panny's 24P footage in various situations - like uncharacteristic ghosting or fringing, for example. I haven't had these problems, but I've only operated in one set workflow.

Have any of you had strange issues come up as a result of digitizing this material?

Maybe you went into Premiere, or an Avid, or used the Panny tape instead of Sony, or something else. And if so, how did you solve the issue?

Thanks for any feedback.

Dan "Inspector Clouseau" Coplan
Cinematographer/Editor/DVD Authoring
www.dancoplan.com



Dan Coplan wrote :

>Have any of you had strange issues come up as a result of digitizing >this material?

I have not had an issue when digitizing 24P from this camera.

Steven Gladstone
Cinematographer - Gladstone Films
Cinematography Mailing List - East Coast List Administrator
Better off Broadcast (B.O.B.)
New York, U.S.A.



Dan Coplan wrote :

>Have any of you had strange issues come up as a result of digitizing >this material?

You have to make sure that you're using the same pulldown settings on the camera and the NLE -- there's standard 2:3:2:3 pulldown (good for Avid Film Composer and Symphony and other non-Firewire systems) and there's also "advanced" 2:3:3:2 pulldown, which is great for Firewire-based editing systems only.

If you are using the wrong settings, you will have stuttery output.

Jeff Kreines



Dan Coplan wrote :

>I've recently heard about people having odd experiences when >digitizing Panny's 24P footage...Have any of you had strange issues >come up as a result of digitizing this material?

Yes.

I've had timecode issues when capturing 24P standard using a non-DVX100 to play the tape. I haven't fully explored this but here's what I know so far:

1/. FCP 3 remained "awaiting timecode" when playing the tape in a 1-chip Canon mini-DV cam.

2/. iMovie was able to capture clips from the same tape and camera.

3/. The Panasonic DV52 1-chip won't display timecode in its LCD but Vegas 4 captures it just fine.

I don't have the DVX100, Canon cam, or a DVX100 tape in my possession at the time but if I did I'd perform the following additional tests:

a. Try (1) with the latest version of FCP 3 - I THINK the FCP 3 above was 3.0.0.
b. Try (3) with FCP as opposed to Vegas.
c. Try 24P advanced with all of the above configurations.

Joe Shapiro
Editor
Seattle WA



Is there an output problem with any specific decks? Or is there a deck that works well with the 24p normal pull down cadence?

With clients that I (and Dan) have worked with, there has never been problems digitizing via the camera. All the problems seem to begin when clamshells or decks have been used to digitize. Anything from ghosting to a mysterious moraying or fringing...any body have experience with specific decks or strange image phenomena?

cheers

Mark Eberle
DP



>is there an output problem with any specific decks? Or is there a deck >that works well with the 24p normal pull down cadence?

Pulldown cadence is a non-issue. The recorder on the DVX 100 is a standard 60 field NTSC-type DV recorder, and that's what the material on it is, regardless of the shooting mode. Panasonic has even gone so far as to guarantee compliance with generally accepted conventions about time code vs. pulldown cadence (i.e., all "A" frames fall on time codes ending in 0 and 5, and the time code is always NDF in 24p shooting mode) to ensure that the tapes are no different than a "typical" 24 fps to 60 field NTSC film transfer.

I have never seen as much confusion about a product as I have seen about the 24p modes on the DVX100. Panasonic really has done their best, IMHO, to provide information about how it works and the fact that it creates totally standard DV tapes. But people persist in thinking that the 24p modes extend to the tape itself, and that there is something unique or special about the format, when in fact there isn't.

Mike Most
VFX Supervisor
IATSE Local 600
Los Angeles



>Is there an output problem with any specific decks? Or is there a deck >that works well with the 24p normal pull down cadence?

24p material recorded by the DVX100 is recorded just like any standard 60i material, only with pulldown added, NDF TC, and some metadata in the DataStream for apps that use it to remove the pulldown (like FCP4, for example, though neither Cinema Tools nor DVFilm's Maker program give a hoot).

With FCP I've digitized from 24p tapes using the AG-DVX100, DSR-PD150, DHR-1000, DCR-VX1000, and DSR-11 with no problems. I specifically tried to "break" my captures with varieties of stopped/started scenes, overdubs, timecode gaps, and video gaps; I encountered no problems that were specific to 24p.

I've also done some limited 24p work with in-sync Blade 2 and Vegas 4.0c. Neither one gave me any grief with 24p material.

There *are* decks and camcorders that have "issues" in general, not with 24p but with timecode and with basic FireWire communications. A number of the single-chip Canons (the ZR series, I think) are often implicated in capture problems, though I haven't tested any myself. The Canon XL1 at work has been perfectly well behaved.

Note that is *is* possible in pathological cases to break or interrupt the pulldown cadence on source tapes (the camera does a great job of trying to maintain cadence, but it's possible to fool it--try dubbing scenes back-to-back to another tape in VCR mode, without regard for cadence!). If you attempt a pulldown removal from such a tape, you may find that ahead of the cadence break the pulldown removal is correct, but after it the wrong frames will be removed, especially using something like Cinema Tools that you line up on a shot and set it off, after which it runs blind. Maker won't suffer from this (except possibly in the 5 frames around the cadence break itself) because it works on 5-frame blocks, looking at picture content. FCP? I dunno what it'll do in this case.

To test that the right frames were pulled inside FCP, be sure to set the Viewer or Canvas to 100%, "Show as Sq. Pixels" OFF. Only then will you see both fields in their native form. Alternatively, hook up FireWire output. Any bad frames (broken pulldown removal) will show interlace jitter.

Both Cinema Tools and Maker show you unbuggered native frames onscreen at all times, so they can be used to step through or play clips to test pulldown removal.

Adam Wilt / Video Geek / Menlo Park CA USA



Mike Most wrote :

>The recorder on the DVX 100 is a standard 60 field NTSC-type DV >recorder, and that's what the material on it is, regardless of the shooting >mode...the time code is always NDF in 24p shooting mode

I was simply describing behaviour I've seen playing 24p-recorded tapes in two consumer DVCams. I'm not suggesting that the DVX 100 is doing anything wrong while recording to the tape.

Now that you've mentioned that the 24p footage is NDF, I'll SPECULATE thusly :

Both consumer DVCams I played 24p tapes in record DF only. Maybe they're not completely happy playing an NDF tape.

Similarly, FCP may have "special knowledge" about what formats come out of what DVCams. Or it may ask the DVCam what format to expect. I don't know the deck protocol so again I'm speculating here. If FCP is told to expect DF it may not recognize the NDF timecode that actually gets sent. iMovie uses very different capture code and apparently doesn't suffer from this problem.

So, does this sound plausible or am I smoking something?

Joe Shapiro
Editor
Seattle



Joe Shapiro wrote :

>Both consumer DVCams I played 24p tapes in record DF only. Maybe >they're not completely happy playing an NDF tape.

I've been following this thread about TC anomalies with the DVX100 and it brings to mind a problem I encountered when I first got my machine...2 months ago.

While shooting, I thought it was cool to switch from 60i to 24p not realizing time code world was not going to be happy. Until this past post it never dawned on me that 24p only does NDF time code which would explain a problem I had with some recent DV to Beta bumps. I had a commercial house do it and they took the time code directly from DV to Beta and since the time code went from DF to NDF a number of times, the Avid Media Log system went crazy and wouldn't allow logging to continue.

I had to do the transfers over myself and generate my own TC via my BVW75.

I now have learned NOT to be switching from 60i to 24p on the same tape. You gotta do these little quirky shifts on separate tapes...trust me on that one!

Allen S. Face mire
DP/Director
SaltRun Productions,inc.
Atlanta
www.saltrunproductions.com



Allen S. Facemire wrote :

>I now have learned NOT to be switching from 60i to 24p on the same >tape. You gotta do these little quirky shifts on separate tapes...trust me >on that one!

That's not the case at all. Simply go into the recording settings and change the time code mode from "DF" to "NDF" and your time code will be non-drop frame all the time, regardless of what shooting mode you're in. In fact, you should do this if you're shooting in the 24p modes because the only way you can put color bars on the tape is to go back into 60i mode. Just set it to NDF and leave it there.

Mike Most
VFX Supervisor
IATSE Local 600
Los Angeles



Mike Most wrote :

>you should do this if you're shooting in the 24p modes because >the >only way you can put color bars on the tape is to go back into 60i mode. >Just set it to NDF and leave it there.

I'm from the school (not necessarily the correct school) of you shoot DF if you are doing TV broadcast and NDF is you are doing all else.

I know when I work for 20/20, Dateline, etc., they ALWAYS want DF.

I have no problems going to NDF...I just wish I could get a clear message as why I have been shooting DF all these years when I could be shooting NDF and save the hassle.

I'm bumping my DV to Beta for edit and eventual broadcast, pretty much like the networks still do as I recall, my editor would rather have NDF. We use stock footage from time to time and it generally comes from CNN which is always DF.

I hate mixing and matching...one TC format would be lovely to me!

Allen S. Face mire
DP/Director
SaltRun Productions,inc.
Atlanta



>I now have learned NOT to be switching from 60i to 24p on the same >tape. You gotta do these little quirky shifts on separate tapes...trust me >on that one!

Haven't tried it, but I would suspect that so long as you maintain NDF for whatever mode you're in, the timecode will remain true. Don't forget your REC CHECK button to realign the timecode when you power off/on, change modes, etc.

Dan "Trusting of Timecode" Coplan
Cinematographer/Editor/DVD Authoring