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#1 Jon Rosenbloom

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Posted 30 April 2008 - 02:06 PM

Sorry for the re-post, but I guess no one scrolls down to the bottom of the forums page:

I'm trying to get my head around some post issues that seem to be obscuring some halfway decent footage I've recently shot.

Shot a graduate school film in super 16mm, composed to 1.85:1 lines on the groundglass. Transferred to HDCAM @ 24p, but the school has only DVCPRO-HD decks, so Post-Works dubbed down to DVCPRO-HD @ 60i, w/ - I assume - a 2:3 pulldown. Isn't this the same (in terms of motion and timecode) as if we had shot 24p on a Varicam? Yet, lots of editing time has been spent on dealing with wandering time-code, and weird motion artifacts (stutter) , including trying to "reverse telecine" the footage.

Per my DP deal, I went to collect my footage. We created a sequence, and exported a .mov in dvcpro hd, at the "current" frame rate but the resulting QT (on the computer monitor) was terribly interlaced and ran too fast. I understand computer screens magnify the interlacing of interlaced footage, but it seemed really magnified. How late in the process can we "de-interlace" the footage? And, do we keep an interlaced version for festival projection?

I mentioned the aspect ratio because I want to make sure that it gets projected in 1.85:1. I assume we put some frame leader (and color bars) at the head of the film and the projectionist will size the film to the theater's screen. I wonder, though, if we bother adding our own mask in Final Cut (it's such a small mask, anyway), or do we leave it up to the projectionist?

Basic questions, but thanks.

Here's some stills from the shoot.

[attachment=3971:Pablo_Cab.jpg]

[attachment=3972:Emily__apricot_CU.jpg]

[attachment=3973:Mister_Apt_Night.jpg]
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#2 Michael Most

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Posted 30 April 2008 - 03:54 PM

.... Post-Works dubbed down to DVCPRO-HD @ 60i, w/ - I assume - a 2:3 pulldown. Isn't this the same (in terms of motion and timecode) as if we had shot 24p on a Varicam?


No. The Varicam includes pulldown flags in the vertical interval to indicate the "actual" 24 frame sequence (they're actually in the time code user bits). There is no way to do that from other devices. Since you can't field edit on these machines, there is no way to record with cadence control, so the cadence is going to be random at each edit point. The more sensible way of getting DVCProHD footage from telecine is to receive it as files, mot likely Quicktime files, that you would use directly in your editing software. If you do it that way, the files can be 720 or 1080 and be 24p already, having been digitized from a "true" 24p source.
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#3 Jon Rosenbloom

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Posted 02 May 2008 - 01:02 PM

"Since you can't field edit on these machines, there is no way to record with cadence control, so the cadence is going to be random at each edit point."

So you're saying that dubbing from HDCAM to DVCPro HD doesn't include the pulldown flags, and therefore the resulting dubbed footage will have a random cadence? This kind of syncs w/ what I've been hearing from the director. Sounds like if Post-Works had just done the telecine 60i, we wouldn't be having these problems.
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#4 tylerhawes

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Posted 02 May 2008 - 03:27 PM

It would've been best to just capture from the HDCAM to DVCPROHD 23.98 files. Or at least dub to 23.98 DVCPROHD tapes. This is a common mistake in post workflows, unfortunately, and is a real nightmare to deal with when you're this far down the road.

At this point if you want to get back to 24p the only real option is to have someone go through shot by shot finding the cadence and rendering out (like in After Effects). Or you might take care of it in a specialized system like a Terranex or Snell & Wilcox.
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#5 Jon Rosenbloom

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Posted 02 May 2008 - 06:52 PM

What if we don't care about getting back to 24p? I'm comfortable w/ the notion that once it goes to tape, it's interlaced. My only concern, really, is that the motion appear smooth and at the correct speed! (I would have been happy w/ telecine Spirit to Digi-Beta, but we got a good price on the HD transfer.) Post Works is holding on to the HDCAM tapes, so if we can't output something acceptable from what we've got going, maybe we can bring them a hard drive and go tapeless for our selects. BUT, eventually, a .mov is going to be produced and a tape handed in to a festival and projected onto a theatre screen, so - I assume - there's going to be a 60i version at some point.
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#6 tylerhawes

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Posted 02 May 2008 - 07:01 PM

If the 24p > 60i conversion is done properly, you shouldn't have troubling artifacts like you described. Motion should be smooth, not stuttery. Something is wrong here.

In this day and age, there's no good reason not to post 23.98 and only go to 60i in the end as one of your masters. Anything else is a mistake in my opinion as it closes your options and introduces a host of issues unnecessarily.
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