I will be shooting a short over 6 days in March. I will be recording sound on a Zoom F4, and video on a BM Ursa Mini Pro 4.6K camera. I have a snake with XLR for audio feed and a BNC feed to carry TC. The camera will jam to the F4. Is there an advantage to using free run Internal Time Code, resetting each morning to 00:00:00;00 (or not resetting and letting it run for the duration of the project) or using Internal RTC (day/date)? The camera appears to jam to either one, but the F4 manual implies the Int TC is more "accurate" than the RTC.
Using Zoom F4 Timecode
- Thread starter ric8138
- Start date
Noiz2
Sound Ninja
Runtime TC if that is what they mean by RTC is probably not a good idea. Runtime starts and stops the clock with the recording so your camera and the F4 will not be in sync. I also would not set it and run the rest of the project with out renaming. The clocks these days are very good but over multiple days you will almost certainly see drift.
Time Of Day TC oly helps you if you can jam the clocks to the same TOD, and I doubt you can. So in your shoes I would jam in the morning and after lunch (or any long break) and maybe after any battery change. It's kind of pointless to deal with TC if you don't make sure it stays totally in sync. At a minimum I would periodically check that they are still in sync, but really re jaming will take the same time so...
Time Of Day TC oly helps you if you can jam the clocks to the same TOD, and I doubt you can. So in your shoes I would jam in the morning and after lunch (or any long break) and maybe after any battery change. It's kind of pointless to deal with TC if you don't make sure it stays totally in sync. At a minimum I would periodically check that they are still in sync, but really re jaming will take the same time so...
Glancing through the F4 manual, it looks as if RTC mode actually means that it jams the TC to the internal date and time information, and also re-syncs internally every time the unit is power cycled and every time date/time info is altered. It runs continuously even when recording is stopped.
Internal Free Run is your best bet here, and I usually manually set TC to time of day and just let it go from there (unless the client requests differently). If you’re constantly connected with TC from recorder to camera, there’s no need to re-jam TC throughout the day because it’s always connected. Re-jamming periodically is good practice if you’re connecting the BNC cable just long enough to jam.
Internal Free Run is your best bet here, and I usually manually set TC to time of day and just let it go from there (unless the client requests differently). If you’re constantly connected with TC from recorder to camera, there’s no need to re-jam TC throughout the day because it’s always connected. Re-jamming periodically is good practice if you’re connecting the BNC cable just long enough to jam.
Basically, the Ursa follows the F4, whatever it's set for, when they are connected. I plan on leaving them connected for the majority of the shoot which is interior/dialogue work to give me an audio track. The Ursa TC will continue on if disconnected, and is now reputed to be quite accurate. I plan to disconnect the snake and let the 2 units run separately in parallel when shooting the action/outdoor stuff with a camera mounted shotgun for a scratch audio track as backup, and just reconnect the BNC/TC when doing a battery change on the Ursa to re-sync.
You might look into getting a pair of Tentacle Sync devices. If you're going to be using TC, they can make things easy and cable-free. You'll need to get a couple of the BNC cables that are sold separately.
One note about the Tentacle Sync, though: it's a product from Germany and it comes out of the box set for 25fps. It will not automatically adjust its frame rate to incoming TC, so each box will need to be set individually to the needed frame rate (easy to do via mobile app) if you're using, say, 23.98. After that, the slave units will sync to the master with no issue.
The regular disclaimer on time code: if your post-production team is not (or if you ARE the post team, you are not) prepared to utilize time code in the post workflow, it can be more trouble than it's worth. A dumb slate can be perfectly suitable, as long as script notes and sound reports are kept.
One note about the Tentacle Sync, though: it's a product from Germany and it comes out of the box set for 25fps. It will not automatically adjust its frame rate to incoming TC, so each box will need to be set individually to the needed frame rate (easy to do via mobile app) if you're using, say, 23.98. After that, the slave units will sync to the master with no issue.
The regular disclaimer on time code: if your post-production team is not (or if you ARE the post team, you are not) prepared to utilize time code in the post workflow, it can be more trouble than it's worth. A dumb slate can be perfectly suitable, as long as script notes and sound reports are kept.
P
PeopleCanFly
Guest
I own a single Tentacle Sync and the Zoom F4. From my testing, I've noticed they stay in sync for quite a few hours at a time. I left them both on overnight and still had perfect sync in the morning. Of course, you should test everything before doing it for real, and I always re-jam after a few hours just to be safe.
Also, if you power cycle the F4, you need to re-jam the Tentacle. Other than that, I've had zero issues using a single Tentacle and the F4. I figured it'd be helpful to know if budget is an issue.
Also, if you power cycle the F4, you need to re-jam the Tentacle. Other than that, I've had zero issues using a single Tentacle and the F4. I figured it'd be helpful to know if budget is an issue.
Thanks all. The Tentacle sync keeps coming up, and it sounds like a good product. Maybe next job (that pays). I'm really just shooting this short to help build a narrative reel and sort through this new gear. I always just did the dumb slate/audio sync in the past, but want to try TC out. I will have a scratch audio track on the video if the TC fails for any reason. They claim that, unlike the earlier Ursa cameras, the BM UMP 4.6K version will hold sync for a day or until the battery change. The TC route looks like it will be easier for matching up dailies (shooting RAW) and transcoding for the edit. Thanks again.
Run&Gun
Veteran
Well, the idea(and correct way to do it) is that you have a sync box on every piece of equipment that needs to be/stay in sync. Unless it's something like a Sound Devices recorder with a high quality Ambient TC generator/reader built in, in which case you would be safe not having a sync-box on the SD, but jam all of the sync boxes to it and then put the boxes on the camera. That's how we usually do it.
ric8138, are you shooting this in NC?
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Noiz2
Sound Ninja
Interesting. I question what is going on here though. First because the reviews have shown very little drift with the F series and because the TC is not a "sync" connection. You are just making the TC stay the same it has no ability to keep the recorder "in sync" with anything. So if your audio is drifting then? something else is going on. On analog decks TC was literally used as a sync connection between devices and with a synchronizer varry the run speed to keep devices in sync. With digital TC is just a start time stamp in the meta data header.
Of course you may well be saying that your TC was drifting. In that case I would check with Zoom because as I said a fair number of people tested the TC clock and found it to be very stable so you may have a bad unit.
Run&Gun
Veteran
OK. Just curious, because your timeframe and equipment(Zoom F4) sounded almost exactly like an email one of my audio guys received this past weekend from someone preparing to shoot a student film.
Good luck!
We found that if we left the Zoom run without a box, after only 4 hours it was already off by at least one frame compared to two Alexa's minis (which remained perfectly aiigned). All three were jamsynced at the start of the day.
However, are you saying that the TC in is merely for the purpose of jamming and that it does not continue to read a sync box like the Tentacles in a continuous manner ?
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Audio does not record continuous time code. It stamps the starting TC information into the metadata at the file header for any one recorded sound file.
The F4’s internal TC generator still keeps running, though. By using something like the Tentacle Sync, jamming the recorder to that and keeping the box connected to the recorder will ensure that the time code does not drift through the day and that later takes are still in sync with the cameras.
Noiz2
Sound Ninja
True with digital. Part of the problem is that a lot of people who dealt with TC on a regular basis are older (like me) and TC was used for both with analog tape. So there is a fair amount of info out there that is not wrong but doesn't apply to digital files.
I mean really today with a file it's not even positional really. It's a start mark that software uses to count from and that calculation is the real positional information. With analog video or audio tape you could look at any part of the tape and get an actual TC reference that was conected to that spot on the tape.
GaryNattrass
Veteran
Yes and for around 25 years now we have just used timecode to know where we are in the programme as it is the video (50/60hz) syncs and sample rate that define the internal sync of edit systems etc.
I bet if people put a clapperboard on a take then check sync all will be OK and it is only the timecode readout that has drifted.
I don't see it as a huge problem and these days in digital the edit video displays are probably out of sync anyway.
Now in the old days we just had a pulse of 50 or 60hz and some sprocket holes and we put some rubber numbers on to know where we were on the take in post production.
As a side note we just did a new News studio at SKY TV in the UK and with all the video delays required for virtual studios etc we have to watch everything up to 19 frames out of sync. Std delay without VR is 7 frames and we just dip into a feed to check sync every now and again.
We do this as we have to keep all the audio in real time for talkback and foldback systems etc and it is always amusing to remind everyione that it is actually the pictures that are out of sync and we are kind and generous in audio to dial in the various delays to make it all work OK.
I bet if people put a clapperboard on a take then check sync all will be OK and it is only the timecode readout that has drifted.
I don't see it as a huge problem and these days in digital the edit video displays are probably out of sync anyway.
Now in the old days we just had a pulse of 50 or 60hz and some sprocket holes and we put some rubber numbers on to know where we were on the take in post production.
As a side note we just did a new News studio at SKY TV in the UK and with all the video delays required for virtual studios etc we have to watch everything up to 19 frames out of sync. Std delay without VR is 7 frames and we just dip into a feed to check sync every now and again.
We do this as we have to keep all the audio in real time for talkback and foldback systems etc and it is always amusing to remind everyione that it is actually the pictures that are out of sync and we are kind and generous in audio to dial in the various delays to make it all work OK.
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This is exactly what we ended up doing, because when it was not tethered we found it drifted after only a few hours. So whatever the other discussions are here about the theoretic's, this was the practical reality that we dealt with.
With how easy TC is to use, then it is very sad state of affairs indeed if post won't utilize TC at all.