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Removing pulldown in Avid / Making 29.97fps 23.976fps at capture
Ok, so very long story short:
I am editing a full length 2,5 hour live performance that was shot with 14 different cameras and now exist as 60 tapes.
Original tapes are HD CAM 1080i 23.976 masters but I also have DVCam dubs. Due to the size and length of footage I plan on capturing and editing from these SD dubs and then re-digitizing from the HD masters in the final online. They want final delivery to be HD CAM 1080i 29.97.
My first problem is that whoever did the dubs are not able to tell me whether they added the pulldown so I don’t know whether the DV Cams run at 29.97fps or are identical 23.976 dubs (if that’s even possible on DV Cams). Is there any way to confirm this? When capturing into a 30i standard Avid project I see the duplicated frames so I am ASSUMING that means the pulldown was added.
So what I am trying to figure out:
– If I am wrong and these dubs do in fact run with an identical frame rate of 23.976, just like the HD CAM masters, will it be a problem free process to recapture all material and “upres” my project to HD since both HD and SD tapes should have exactly the same timecode?However, if these dubs are 29.97 I can’t really do an edit with this frame rate as it will cause timecode problems in the online when trying to upres and refer to the HD cams, which run at 23.976 right? So I need to somehow make these dubs 23.976 at capture. Someone tried explaining that I could do that by making sure capture starts at an “A” frame in an Avid 23.976p project, but that gets a little complicated for me.
After some research it seems Avid has a “Film and 24” setting where I can decide the pulldown phase. With this function it seems Avid automatically takes away the pulldown at capture. When stepping through the footage captured I no longer see duplicated frames. Does this in fact mean that activating this function in Avid removes pulldown at capture and that if I bring all footage in this way it will be 23.976 (as that’s my project setting?)
That was a lot of explaining. But if ANYONE could please help it would be amazing. I am on a private Avid Media Composer 3.0 set-up with no access to an HD deck and need to know I am safe to work from these dubs and that I do not do any major bloopers before starting a 60 tape capture.. and following 29 song performance edit!
Please help..
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1 Reply
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Short answer, if your final delivery is 1080i 59.94 (29.97 frames), then edit in a 29.97 SD project and you’ll be happy. The HD deck, SRW 5500 for example, can spit out a 59.94 conversion and the TC will match.
If you have to deliver a 23.98 master, which fortunately for you is not the issue, then yes you work in SD 23.98. The DV dubs have pulldown added. If they were done correctly, Avid will remove the proper extra fields on capture. There is potential for error in the dubbing process as follows:
1: If a bozo did the downconverts, he could have changed the TC from Non-Drop (the only thing that exists in 23.98) to Drop-Frame TC. This means when you try to go back and conform to your HD masters, there will be hell to pay.
2: If the HD deck doing the downconverts was not locked to Tri-Level and normal Sync that were also locked together, then the pulldown phase can be incorrect. This way even if you work in a 23.98 SD project, and Avid assumes the “A” frame cadence is the proper, you will get stuttery footage to work with.
For those reasons, working at 23.98 for a 59.94 delivery makes no sense. Also, should you want to add any archived footage that is 29.97, it will be simple in 59.94 and a PITA in 23.98.
Terence Curren
http://www.alphadogs.tv
http://www.digitalservicestation.com
Burbank,Ca
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