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Brendan Maghran
23.976 ntsc
on Sep 4, 2012 at 3:36:59 am

23.976 NTSC project

Just a couple questions about this format...

Is it not true 23.976 fps?

In order to add tape names or import audio (to correctly sync) I have had to import into a 23.976 1080p project. Also, the master timecode for the source monitor runs on 30fps. Why?

I'm just interested.


Brendan


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Shane Ross
Re: 23.976 ntsc
on Sep 4, 2012 at 5:51:46 am

[Brendan Maghran] "Is it not true 23.976 fps?"

It is.

[Brendan Maghran] "In order to add tape names or import audio (to correctly sync) I have had to import into a 23.976 1080p project."

Yes, and that's how you know it's true 23.976.

[Brendan Maghran] "Also, the master timecode for the source monitor runs on 30fps. Why?"

Just what Avid defaults to...because it's drop frame and time accurate. Because 23.98 isn't DF and isn't time accurate. You can easily change that...click on that time and choose 24p NDF.

Shane
Little Frog Post
Read my blog, Little Frog in High Def


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Job ter Burg
Re: 23.976 ntsc
on Sep 4, 2012 at 6:27:02 am

You should certainly be able to change tapenames or timecodes when in 23.976p NTSC.

The MTC is TC30 because there is no such thing as an NTSC tape with something other than a TC30. Meaning that any film-to-NTSC-video process would mean source tapes have TC30, and if you were to play out a sequence to an NTSC deck (which was always assumed at the time), that deck would have a TC30 as MTC.

As said, Avid lets you calculate, track and display a TC24 anyway. It's just that base TC in NTSC is always 30.

In 23.976/1080p projects, the TC base is TC24.


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Michael Phillips
Re: 23.976 ntsc
on Sep 4, 2012 at 10:58:10 am

Job is correct - basically SMPTE does not define an NTSC format at 23.976 or 24 frames per second. So from a metadata perspective, 30fps NDF or DF represents the video format being captured while the actual media is native 23.976 for editing. 1080p on the other hand does have a 23.976, and 24 defined by SMPTE. 720p behave like NTSC again.. SMPTE.

But working in NTSC 23.976 still allows you to track 24fps timecode in two dedicated columns - you can derive the 24fps based on the START and Pullin columns by doing a command-D or control-D of the START timecode column and selecting TC24 or AuxTC24 from the pop-up column. MC will not track both timecodes. It will also track 25fps, 30fps with no pulldown, PAL with pulldown, etc. basically representing any type of format that might have 24fps on it - whether it is native or not.

Once HD hit the market and there was a 23.976 and 24 defined, most "24p" projects gravitated towards towards those project types to have the 1:1 timecode relationship in the START column. DNxHD36 was added as the offline resolution just as 14:1 was for NTSC. DNxHD36 is roughly 3x the storage needs of 14:1 without about 10x the picture quality. :)


Michael


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Brendan Maghran
Re: 23.976 ntsc
on Sep 4, 2012 at 6:51:13 pm

Thank you for clarifying. The show im working on is my first 23.976 ntsc experience. We are working with long-gop media from canon c300. Is there any way to get both source and record tcs to match? Record monitor counts in long gop a,b,c frames but source does not, obviously throwing tcs off.


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Shane Ross
Re: 23.976 ntsc
on Sep 4, 2012 at 6:57:14 pm

[Brendan Maghran] "We are working with long-gop media from canon c300."

Hey! Me too. Shooting C300 at 1080p 23.976, consolidating to the media drives, but working native. Been doing this for 3 months now.

[Brendan Maghran] "Is there any way to get both source and record tcs to match?"

Yes. Set your RECORD monitor to SEQUENCE>TIMECODE>24>MASTER. Now you are monitoring at 23.976 non-drop. And it will match.

NOTE: This is non-drop frame code. Meaning that it isn't time accurate. So if you look at the timecode at 45 min...say 45:17:18. In ACTUAL time, that is 45:20:15...about 3 seconds difference. Because drop frame timecode is actually time accurate, and non-drop is not. I just want you to know that. I have two rows of info up so that I can monitor my 24NDF code and what it would be at 30DF...so I know what my actual timing is.

Is your show intended for broadcast? Does it have strict time requirements? What are the delivery specs?

Shane
Little Frog Post
Read my blog, Little Frog in High Def


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Brendan Maghran
Re: 23.976 ntsc
on Sep 4, 2012 at 8:33:44 pm

Yes it is a network pilot. We're delivering 23.976 actually and then the network does their own conform to 59.94. We will be monitoring both 24/30 tc rates like you just noted just so we know we're cut to time. I changed the source to 24fps, although for some reason it wasnt an option in the source monitor until i entered multicam mode.


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Michael Phillips
Re: 23.976 ntsc
on Sep 4, 2012 at 9:08:07 pm

You shouldn't need to be in multicam mode to see source. Once values are set in the TC24 column based on the conversion method I mentioned in my last post, they are available above the monitor.

Michael


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