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Timecode problems with 59.94, 24p


jacquesstar

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Okay, so here are my timecode settings:

 

Panny HDX900: 59.94, 24p mode, NDF

 

Sounddevices 664: 24p timecode Ext/Cont. timecode

 

Denecke TS-C slate: postion 3 for 24p. Slate and 664 are jammed via lemo cable, sometimes unplugging slate to go slate something.

 

Timecode drifting on camera, slate and recorder are the same.

 

Don't have the HDX900 any more but have my HPX3700 sitting on the shelf, so I could do a test and put it in 59.94, 24p with the same settings.

 

Theories so far: 

 

1. wrong setting in one of the devices

2. i dropped my Denecke slate on the gravel once or twice, maybe the crystal got busted?

3. Sounddevices 664 has latest firmware, but maybe a bad crystal?

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Actually, the Denecke devices can do straight-up 24.00 TC:

 

Rotary Switch Settings
0) 30 frame TC 
1) 29.970 frame TC
2) 25 frame TC 
3) 24 frame TC 
4) 23.976 frame TC / Auto
5) 30 frame TC 
6) 29.970 frame TC 
7) 25 frame TC 
eight) 30 Drop frame TC 
9) 29.970 Drop frame TC
 
I don't use the drop-frame settings on my slates very often, but they can do it. I have worked on 24.00fps projects before, and I believe the slates can work either in mode 3 24.00, or in Auto.
 
In this case, most of the Panasonic camcorders do actually shoot at 29.97NDF, and I believe that's the correct rate, compatible with shooting at 59.94. 
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Ive had that same exact scenario (except using a 788T). When I would simply jam the camera at 29.97 it worked fine. But when I stuck a lockit on it the image was jittery, which was when I discovered the issue. In the case of cameras running 59.94 your best bet is to just jam it. The HDX900 keeps time pretty well, so do it in the morning and at lunch, or after any power down and you'll be fine.

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Okay great, will be doing a bench test within the next couple of days. Jamming my HPX3700, HPX370, 664 and slate, and then disconnecting all of them and letting them run for a couple of hours to see what happens. Will have both cams in 59.94, and 664 in 59.94 with the slate in 29.97, since there is no 59.94 on it.

 

Thanks y'all for your help.

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I'll take Theory 1 (Robert Sharman version)

" Timecode drifting on camera, slate and recorder are the same. "

BINGO...

 

" Panny HDX900: 59.94, 24p mode, NDF

 

Sounddevices 664: 24p timecode Ext/Cont. timecode "

Panavision ??

there is there is no 24P SMPTE TC rate...for Panavision or SD, or anything!  it is either 23.976 (non-integer) or 24.000 (integer) FPS; there is no 59.94 SMPTE TC..(or 60.000, either) .but 59.94 would indicate non integer frame rate

 

30FPS DF is non-SMPTE and implementations vary

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If the final delivery is going to be at 23.98, wouldnt it make sense to cross-jam the camera with your TC source set at 23.98, rather then 29.97?  Of course, this is a decision that should be made by post...

 

On the other hand, why is it that I've been getting so many jobs shooting in 59.98?  I understand that this is typical for [live] sports so they can pull slow-motion shots off the same, but most of the jobs in question have no intention of slowing anything down at all. 

 

e.

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Yes they can do 24fps - I was clarifying that 24p is not a setting on audio gear.

 

Actually, 24.00 is a timecode menu item on all the Deva and Sound Devices recorders I've used.

 

788timecodemenu_zpsf324c6bd.jpg

 

But... I've never used 24.00TC for recording, and I usually try to talk my clients out of it. It's very frustrating how few camera operators and directors understand the problems of 23.98 and 24.00. I've encountered quite a few productions where they've inadvertently mixed 23.98 and 24.00 timecode, with disastrous results.

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When Sony originally developed their CineAlta cameras they came up with the term 24P  .  The "P" stands for Progressive.  Previous to the development of HD video all video in the USA was NTSC at 29.97 FPS interlaced.   The 24P is progressively scanned instead of interlaced and (confusing as it is) was always actually running at 23.976 FPS.    They all ran at 23.976 ;to be compatible with existing video monitors and displays that were clocked at 59.94 HZ. house sync and interlaced to get 29.97 FPS.  Only later did they come up with True 24.000 FPS frame rate for file based editors (no tape machines or standard video monitors involved)  There was no end of confusion over this because Film Shot at 24.000 went through 3/2 pulldown during transfer to tape to end up at 29.97 and had to be slowed down .1%.  Meanwhile 24P video shot at the same time was real-time at 23.976 with no slowdown.  So the two would not stay in sync if shot at the same time and played at the standard 24 FPS frame rate.    Sony always had a frame rate of 23.976 and audio at AESEBU digital standard of 48.000KHZ

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We're both saying the same thing here. 24fps is a setting on audio gear. 24p is a camera setting. 24p does not mean 24fps.

 

Ah, I get it. I agree: 24P has no meaning for sound. Only the frame rate is an issue, not whether it's progressive, interlaced, or segmented. (As John Lennon said, "it's nothing to get hung about.")

 

What's interesting is that in post, 99.9% of the time when a client or a post person says, "24P," what they really mean is "24Psf" -- the standard used in HDCam-SR and many similar tape formats. Sony also has an SR file-based format using similar standards. Both are still at 23.98fps.

 

It actually doesn't matter: 24P and 24Psf both come out the same way and can be cross-converted (in terms of video). Doesn't affect audio at all, assuming timecode is compatible. When the broadcast air delivery copy is made, it goes back to 1080i (not P at all), and that's what gets broadcast. In the case of Fox and ABC, they do get 720P at the very end, also at 29.97DF.

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If the system frequency setting on a Panasonic HDX900 is 59.94, the timecode is 29.97. The 24P video is via electronic pulldown and there is also NO drop frame timecode setting available in that mode.

 

Be aware, however, that if the video is also being recorded to some sort of solid state recorder, frame rate conversion and scaling may come into play. The camera is a tape-based device and I've done jobs with them recently but always to an external video recorder.

Best regards,

Jim

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