Newcomer to 24p ntsc, pulldown problem?

[Bill Stephan]

Usually there is one punch per reel of film, and there is new time code for each film reel. The punch is the reference point for establishing the A-frame. So there should never be case where A-frames are on timecodes ending in anything other than 00, 05, 10, 15, 20, or 25. Otherwise the film-to-tape session was done wrong, or the tape was re-striped, or something else happened.

Bill Stephan
Senior Editor/DVD Author
USA Studios
New York City

[Moztu]

Hi,

Thanks, yes that is what I was starting to figure out.

I will talk to the lab, but what they are doing is telecine into digibeta and then dub the tape into DVCam for us to digitise. Could that be the problem?

[Bill Stephan]

I doubt if the dub is your problem. It should be a faithful copy of the Digibeta. I would go back to the people who did the film xfer work and explain your concerns. Maybe there is some wierd error that crept into the process. If the job was done correctly, you will learn something from them. If they screwed up, hopefully they will learn something.

Bill Stephan
Senior Editor/DVD Author
USA Studios
New York City

[Moztu]

Hi,

I have done through the footage slowly and:

I have identified one of the problems. The capture is sometimes off by few frames due to the different clips having the same in as the out of the previous shot. so the TC being off by one or two frames I think comes down to that. So I learnt something there.

About the punches not being on “A” frames: I think that the problem starts when they have two camera rolls spliced together too close, so the punch that should be at the beginning of the roll ends up being at the end of the previous roll, so everything is off after that.

the problem is, when I tell them that the punch should always be on an “A” frame, they ask why should that be so? And honestly, I don’t understand it very well myself, so if anybody could give me an explanation I can give them I would be very grateful.

thanks a lot.

Iurre
moztu

[Michael Phillips]

Are you getting a FLEx file or an ALE file with the transfer? You will want to pass this through Avid Log Exchange to “clean it” meaning it will remove all overlaps done in telecine. Usually telecine is done a bit more carefully to not have these issues.

Avid does not care what the pulldown cadence is as long as it is accurate of the transfer. This should be part of the FLEx file. “A” frames are a recommended practice since it is easy to verify accuracy of a transfer and capture when all timecodes end in :x0 and :x5 for non drop timecode.

Are you capturing via a Mojo or directly over FireWire? Are you capturing on the fly from an imported log file?

Michael

anything 24fps

[Moztu]

Hello,
I am capturing directly firewire. batch capturing from the log, I pass it through avid log exchange, but I am not cleaning it, so I will try that next.
About the “A”, the thing is the avid thinks it’s an a even if it is not on a x0 or x5 frame. would that still be ok?
the american editor is telling me that it should always be on an “A” and I should not see any image before the punch in each reel. sometimes the punch might be a few frames into the clip?

[Michael Phillips]

It is a recommended practice that sync points and punches fall on an “A” frame and on 30 frame non drop timecode ending on 00, 05, 10, 15, 20, and 25. But as long as the timecode to pulldown relationship is correctly defined in the ALE file then that also is fine – Avid allows capture of any pulldown on any timecode since in some cases it cannot be controlled.

But in your case it sounds like the capture is still not correct – make sure you are viewing the sources with the timeline in green/green mode to check for proper capture. Where are these transfers being done? There could be an issue with the dub – it is not done “field” accurately what was an “A” frame is actually a “C” frame as far as the capture and reverse telecine is concerned. Try changing the Pullin value to something other than “A” and recapture to see if you see a pattern.

Michael

anything 24fps

[Moztu]

Hi,
I went through the start of all the clips field by field and they are all in an “A” frame following the instructions found in: https://www.zerocut.com/tech/pulldown.html
And it is actually the one that seems to be more acurate, if it wasn’t because “C” frame is always a split image. half of it from one frame, and half from the other frame.
Could it be that the “normal” pulldown promised with 5.5 is not working correctly? Or else we have a configuration problem with our system? Has anybody heard anything like this?
we had problems with audio as well and had to start importing bwf files on 4.8 instead.
Thanks
Iurre
moztu

[Michael Phillips]

Have you tried this in v.5.5.2? Make sure you have OSX 10.4.7 as well as a Super Pro Dongle for that version to work.

Michael

anything 24fps

[Moztu]

Hi,

Apparently it is a problem with either our system or the version of the program. our editor in NY just received two of our tapes and the project, batch digitised it in another system (not xpress pro, I don’t know which but I have asked him), and everything seems to be fine on his side.

it is 5.5.2, but I thought it was better to work on 10.4.6 for some reason. I will try upgrading the OS.

Thanks.

Iurre