Anyone using variable frame rate DVCPRO HD?

[Chris Bell]

This site may be of some help:

https://www.kenstone.net/fcp_homepage/dvcpro_hd_workflow_balis.html

Chris Bell

[Uli Plank]

It looks like working in 24 fps (actually 23.98) will be the way for us European users too. You’ll need to edit in a 24 fps timeline and later speed the stuff up to 25fps by conforming in CT. To avoid the speed change you can shoot 25, use the FRC for a mild slow-down and the end result will be correct in 25 again.

I don’t think that working via SDI is a better option. It might simplify your workflow, but it’s a waste of space and bandwidth and the conversions involved won’t improve your material.

Regards,

Uli

Author of “DVDs gestalten und produzieren”, a book on professional DVD-authoring in German.

[Leo Ticheli]

Hi Uli,
It’s a major mistake not to load via HD SDI if you are doing any effects or layers! You will compromise the quality of the material if you try to go beyond simple cuts-only with a Firewire load. This includes any color grading.

Yes, HD SDI requires more disc space, but it’s certainly worth it if you want to work uncompressed throughout the process. Use Firewire for any purpose other than an off-line edit will do violence to the image quality.

Best regards,
Leo

Director/Cinematographer
Southeast USA

[Uli Plank]

Hi Leo,

you are absolutely right, but for serious effects work one shouldn’t use a highly compressed format from the start…

AFAIK the Varicam is limited to 960 by 720 pixels and the recording on tape is 100 mbps

[Leo Ticheli]

Hi Uli,
Forgive me, but I believe you are missing the point.

No, loading via HD SDI will not improve the quality of VariCam material, but it will keep the post process, effects, color correction, layers, in an uncompressed format which will result in a much higher quality final product than loading via Firewire which has the effect of decompression/recompression with each and every layer, grade, and effect.

Viper? Sure, love to. However, it’s awkwardly tethered to a large array and much more expensive than a VariCam. If you really want the very best image, shoot 65 MM film! Naturally, the best route is to select the cleanest post path for whatever format you choose.

Best regards,
Leo

Director/Cinematographer
Southeast USA

[Gary Adcock]

[Uli Plank] “the Varicam is limited to 960 by 720 pixels and the recording on tape is 100 mbps

[Leo Ticheli]

Hi Gary,
Thanks for coming in on this.

In a way I wish Panasonic had never instituted FireWire loading! Too many people are taking something really meant only for off-line and using it for editing with effects, greatly impairing the image quality. People see it and blame in on the VariCam, when it’s really the fault of the post house.

Best regards,
Leo

Director/Cinematographer
Southeast USA

[Peter Steinman]

Isn’t the data transfered thru firewire exactly the same as recorded to tape (ie. 8bit 4:2:2 100mb/sec) ?

The SDI output of the camera/deck is just using the camera/decks internal codecs to make it ‘uncompressed’ isn’t it ? It is still being converted to 10 bit 4:4:4 isn’t it ?

Are you saying using FCP to go from 8bit to 10 bit is worse then the deck’s conversion ? I don’t see how importing thru firewire into an uncompressed timeline would be worse then importing SDI into the same timeline except for render times. How does it make it look worse ?

I’m just confused not confrontational. I’m still new to all this.

[Paul Mogg]

Hi Leo,
I’m afraid I’m not understanding your argument at all regarding firewire loading and would like to know what I’m missing here.

If you record to tape on the Varicam, you are incurring a certain loss in quality inherent in the compression of the DVCPRO HD format, so let’s start by saying that’s a given (unless you output uncompressed on the fly direct to hard disk from the camera while shooting, and perhaps this is what you’re saying and what I’m missing here).

If you load via Firewire into a Mac from tape, that’s a bit for bit file copy of what is on the tape, and there’s no loss in quality there, just like copying a Microsoft word file from one computer to another.

If you then edit these captured clips in FCP, the original clips themselves do not get changed or degraded at all during editing, the only quality loss occurs when you have to render due to adding effects and filters, or on output. In which case the original camera files STILL do not get changed, it is only the render files that you are viewing during editing that will have quality degradation in them.

So it seems to me that the most efficient workflow with the minimal quality loss (next to recording uncompressed direct from the camera while shooting) is to capture via firewire, edit natively in the DVCPRO HD format, as an offline format. Then, when you are finished editing, re-render out your entire timeline as uncompressed 720p HD. This way the original files from the tape only get decompressed the once, and all of the effects, transitions, filters etc. are rendered out uncompressed also in just the one pass. It seems logical to me that this workflow would produce the minimal quality loss possible, and should actually be equal in final output quality to native editing in uncompressed HD format, while not having to deal with the massive data size of uncompressed HD during editing (again, this is unless the original capture from the camera was uncompressed and DVCPRO HD is avoided altogether.)

It also seem logical that if you were to edit uncompressed, add lots of effects etc, and then fail to do a complete re-render from the original camera files ( that I assume were decompressed after capture ) at the end, you would end up with inferior quality to the DVCPRO HD workflow I’ve outlined, as you would be outputting material that had probably been re-rendered mutliple times during the editing process.

I’d be very pleased if someone could set me straight if I’m wrong in any way here, as I dearly want to understand the arguments being made so as to get the best possible quality for the film I’m working on right now. I’d rather look like an idiot and get it right, if that’s what it takes.

Many thanks,

Paul

[Uli Plank]

Hi Paul,

what you are saying here is exactly my suggestion. It’s very clear to me that any changes or additions other than hard cuts in a timeline set for the original codec will be degraded in quality.
BUT: if you are on a tight budget and are aiming for any other output than HD on tape, like film transfer or HD-DVD, you can pull your stuff via FireWire to a Mac without additional cards or expensive RAIDs. Then you do a kind of offline on a timeline set to the DVCProHD codec. Many things will be realtime here!
When you have finished offlining, you change the timeline to something better, like uncompressed 4:2:2 10 Bit and re-render. Then you hand the result over to film transfer or compression for DVD and you shouldn’t have compromised any tiny bit on quality.

Or am I completely misunderstanding things here?

Regards,

Uli

Author of “DVDs gestalten und produzieren”, a book on professional DVD-authoring in German.