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time code generator

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Craig Alan
time code generator
on Feb 20, 2017 at 2:36:02 am

Would like to start using gen lock and timecode sync for multicam shoots. Not quite getting the chain of connections. I will have 2-3 camcorders with gen lock and timecode sdi/bnc.
I'm planning to buy 2 or 3 Sony FS7 mark ii with the Sony XDCA-FS7 Extension Unit for PXW-FS7 B&H # SOXDCAFS7.
But this has only one (in or out) Timecode and one genlock.

My understanding is that you should use the same length interconnect to each camera from the devise that provides the timecode.

I would be using the Sound Devices 633 which does provide timecode out but only one sdi port to do so.

So what would be the set up? I'll read up on this once I am actually using the work flow. For now I just need to know what to order in terms of set up. What gets attached to what? If one camera is providing the next camera with the timecode then there should be a slight delay between them, Right? And if the third cam then gets it passed to it, I would assume the same problem.

But maybe I'm wrong.

Can I buy a box that would split the timecode out from the 633 to go to the three cams?

Or would I better off with a dedicated time code generator?

Another question I have is that the time code generators I see on bh all indicate they support 1080P. Most of the camcorders now shoot in 4K. Is this supported?

Imacs (i7); Canon 5D Mark III/70D, Panasonic HPX250P, FCP X 10.3, teach video production in L.A.


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Brian Reynolds
Re: time code generator
on Feb 20, 2017 at 7:02:03 am

Timecode and Gunlock are 2 TOTALLY different things.....

Timecode is a 'number stamp' on each frame of media (just like the old 35mm film) the numbers are 'normally' 24hr clock time in hrs / minutes /seconds / frames different shoots often use different frame rates so ALL the units being used should be set at the SAME frame rate.

Normally one device is regarded as the 'standard' and the others should be jambed to that unit occasionally, The audio recorder is normally used as cameras will change when many camera options are used like slowmo.
There are small devices like 'Lockit' boxes or 'Tentacle' boxes are jammed to the 'standard' and then attached to the cameras to supply a continuous feed of code.
So now you will have the 'same set of numbers' on each set of media all you have to do is match them on the time line of the editing.

Timecode is an Identification system NOT a locking system.

Genlock IS a locking system that is used when signals from multiple cameras are switched 'LIVE' just like a TV studio or Outside Broadcast Production through a switcher. Genlock is there to stop a frame roll on each camera video change.
So a camera will use 2 cables attached, the first one is the signal from the camera to the switcher and the other is a cable that times / aligns the control signal. (and yes those cables should be the same length)
There are video switchers made that don't need Genlock and no need for a return to camera cable, this switchers have a frame store on each video input and will allow input from 'NON sync' sources.

Ok my descriptions of both Timecode and Genlock are of a basic nature as a general overview, and should be treated as such.

'Celebrating 40 years of Broadcasting Audio....
Started with Magnetic stripe and Sprocket holes to now Gigabytes and Touch Screen Mixing Consoles'......


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Richard Crowley
Re: time code generator
on Feb 21, 2017 at 1:56:19 am
Last Edited By Richard Crowley on Feb 21, 2017 at 1:59:27 am

What does "multi-cam shoot" mean here? Are you doing on-the-fly, real-time switching between the cameras (as for a live broadcast event or a "live-to-tape" program episode)? Or are you shooting a bunch of cameras in "iso" (where the video from each camera is recorded separately (ISOlated), and then all the camera clips are edited together after-the-fact in post-production processing?

Genlock is more important for live-switching where the cameras must all be in lock-step with each other so that you can switch between them seamlessly. OTOH, timecode is more important for multi-camera, iso production because then the editor knows how all the camera clips correlate with each other.

Some cameras are known to hold their time-sync better than others. Some productions can "jam-sync" each camera to the reference once in the morning and they are good for the rest of the day. Many productions will jam-sync at the start of the day, and then again at the lunch-break (and supper-break for long days). Some makes/models of cameras are notorious for having poor internal clocks and must be synced more often.

This is rather a high-end question and there are many discussions about your very question (and the kind of high-end cameras you are asking about) over on the JWsoundGroup web forum. For example: http://jwsoundgroup.net/index.php?/topic/28186-sound-devices-633-mixerrecor...

If you are hiring a professional sound mixer and/or cinematographer, they likely already know the gear and how to sync it together. If you are DIY, you might want to hire a professional for your first few sessions and learn how to use your gear.

---------------------------------------------------------------------------------
Recording audio without metering and monitoring is exactly like framing and focusing without looking at the viewfinder.


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Craig Alan
Re: time code generator
on Feb 21, 2017 at 2:20:17 am

Thanks Brian and Richard,
I will not be using a switcher, all the cameras would record from different angles. I will be shooting with 2 or 3 camcorders and recording audio using the sound devices 633 mixer/recorder.
I would record scratch audio on the camcorders and the mikes would be used with the mixer/recorder.
In post the media from the camcorders would be edited as a multicam with the audio from the mixer being the audio only track. (though its not called a track in FCP X).

I asked a local pro audio store what they recommended and they came up with this: Tascam CG-2000 - Video Sync/Master Clock Generator.

Would do you think?

Imacs (i7); Canon 5D Mark III/70D, Panasonic HPX250P, FCP X 10.3, teach video production in L.A.


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Richard Crowley
Re: time code generator
on Feb 21, 2017 at 5:05:28 am
Last Edited By Richard Crowley on Feb 21, 2017 at 5:10:36 am

If you want advice on pro sync gear, ask a vendor who specializes in that kind of equipment. Your "local local pro audio store" does not have the credibility of an industry expert like Trew Audio, et.al.

Furthermore, it is not clear that you need anything more. How do you know that simply jam-syncing each camera to your SD633 each morning won't do the job simply and easily? Why do you think you need genlock? Why do you think you need wired timecode? People who produce prime-time TV shows with budgets of millions don't find they need all that. You may be looking for a solution to a problem that you don't have. Or at least you have not demonstrated a need for.

---------------------------------------------------------------------------------
Recording audio without metering and monitoring is exactly like framing and focusing without looking at the viewfinder.


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Craig Alan
Re: time code generator
on Feb 21, 2017 at 5:12:52 am

Well it was Trew Audio and all I wanted to do was sync the audio mixer and the two or three cameras. I asked a lot of people.
I was in a rush cause the application for funding is due and I'm going off the flu and side effects of the flu.

Imacs (i7); Canon 5D Mark III/70D, Panasonic HPX250P, FCP X 10.3, teach video production in L.A.


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Brian Reynolds
Re: time code generator
on Feb 21, 2017 at 5:23:49 am

The camera/s you have mentioned and the Audio recorder all have timecode generators in them.... Just pick one as the standard. Even if its wrong.... ALL the devices will be wrong in the same amount (causing no problem)
My suggestion is the audio recorder 633 and this will not change during the entire shoot where as the cameras may stop / start or do fancy camera stuff which may upset the TC stability. So use the 633 as the 'Master clock' and everything else MUST jamb to it.
You don't need a constant feed the cameras, jambing twice a day should give much less than 1 frame error (per day) over the entire system.

Do tests .... several, to get your head around things, don't just turn up on a job and try and work it out.....

'Celebrating 40 years of Broadcasting Audio....
Started with Magnetic stripe and Sprocket holes to now Gigabytes and Touch Screen Mixing Consoles'......


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Craig Alan
Re: time code generator
on Feb 21, 2017 at 11:34:27 am

Thanks Brian, i need to get the proposal in yesterday so am under pressure. So what gear do I need to use the 633 to jam sync the cameras? Just interconnects? The two devices need to connected when your jamming and then can be disconnected? The 633 uses a 5 pin Lemo. So just get a 5 pin Lemo to SDI /BNC cable, a BNC barrel with two female BNCs and then a SDI cable to the cameras? and connect the two, one at a time? Then repeat as needed?

I was being told by the vendors that I needed a $1000 device for each piece being synced. Thus more expensive than the above plus needed to mount it to each camera.

Once I get the order I can learn too use it hopefully already owning the gear I need. The 633 does not have Genlock only timecode. Isn't Genlock a more solid way to keep the cameras in sync with each other due to variations in the devices clocks? Now the 633 does not have this and therefore that might make the use of it meaningless? Or should I in addition genlock the two or three cameras so they remain firing at the same time? Or is it either or not both? I've been asking BHphoto, Samy's, Trew Audio, and sound devices and here. What do I need, what do I need. Don't even need to figure it out yet just get the order in.

Imacs (i7); Canon 5D Mark III/70D, Panasonic HPX250P, FCP X 10.3, teach video production in L.A.


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Brian Reynolds
Re: time code generator
on Feb 21, 2017 at 2:30:43 pm

For the job described Genlock is not needed as you are NOT switching live.......... Forget the word and every thing to do with Genlock with this job.

Time code is what you will be using.... All you should need is a cable of of less than 2m to join one camera and the 633 for 10 seconds.... then jamb sync the 2 devices, then use that same cable to jamb sync the second camera, then the third camera etc etc etc.

So TC out of the 633 to what ever the TC in (on each camera)

The cameras will then run on their OWN internal TC clocks.... Which will match the 633 as they have been jambed.
This should describe it better if your cameras have no TC or you want to use an external device to sync them.
https://www.tentaclesync.com/#hardware


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Brian Reynolds
Re: time code generator
on Feb 21, 2017 at 2:54:30 pm







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Craig Alan
Re: time code generator
on Feb 21, 2017 at 6:02:52 pm

Thanks Brian. The 633 was not mentioned in the sound devices video but if I can jam sync each camera to the 633 that should do the trick. When folks talk about drifting within 24 hours is that continues shooting or just the amount of time since the cameras were synced. I also remember reading at some point that jam syncing from one of the cameras would be better than using the mixer but my guess is the 633 as you say a better choice since they use good components and because its the audio I am trying to keep in sync. Thanks for your help. I'll forget the tascam and get a short cable 5pin lemon bnc for jam syncing. The length needs to be short or just all that is needed?

Imacs (i7); Canon 5D Mark III/70D, Panasonic HPX250P, FCP X 10.3, teach video production in L.A.


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Richard Crowley
Re: time code generator
on Feb 21, 2017 at 6:47:46 pm

Everything drifts. Every camera, every recorder, every "reference clock". It is a matter of SYNCHRONIZING the different clocks together so that they are all "on the same page". Most higher-end pro cameras have internal clocks that are typically accurate enough to go for 4 hours or even 8 hours before drifting too far (more than perhaps 3-4 frames). So it is a matter of taking the reference (in your case your SD 633) and jam-syncing each camera to it before you start shooting for the morning (or afternoon).

It would certainly be advisable to set up all the cameras and jam sync them to the SD 633 and let them run for as long as your recording media holds out. Then go back and analyze the recorded video tracks and see how much drift each camera has. That will give you a reference point how often you need to jam sync the cameras.

The length of the BNC cable is of no significance. It doesn't matter whether you use a 6-inch cable or a 60-foot cable. And especially when you are using the same cable to sync all the cameras. If you had a cable length of several MILES you might even be a whole frame off. But, of course, the timecode signal wouldn't survive several miles of cable losses. Electricity travels through cables typically at 70% ~ 80% the speed of light.

You did not disclose what kind of production you are preparing for? Is it "reality" where you are shooting unscripted, unrehearsed, reacting to real-world events? Or do you have the luxury of "slating" each "take". Even with timecode the slate (and the clap-stick reference) make breaking down and cataloging the clips and editing ever so much easier.

---------------------------------------------------------------------------------
Recording audio without metering and monitoring is exactly like framing and focusing without looking at the viewfinder.


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Brian Reynolds
Re: time code generator
on Feb 21, 2017 at 10:03:05 pm

You can sync from ANY time code generator..... Just pick the one you want to call 'master' and therefore ALL the others are slaves and must take the code from that master.

In the 'old days' often camera to camera was used to sync (again one master and the others are slaves) often no audio recorder was used, the audio was just split across the many camera audio tracks available.

I have even done shoots where the cameras started in different locations / cities at the start of the day, what we did was set the time code the same as the time read on a Telco dial in service. And yes there was a difference of about a second or so between cameras... BUT that difference was constant for the entire day, a simple 'offset' for that camera was entered into the timeline during editing.... simple.

The drift people refer to is (PER 24 hr period).... shoot for 12 hrs the drift would be half of the errors of a 24 hr period. Shoot for 6 hrs then that would be 1/4 of 24hrs. etc etc.

Im only suggesting a 2m cable as it will fit neatly into a case or bag.

Just something else if you have a crew logging the shoot then all they need to use is a standard wrist watch to quote a Timecode time. The time code will be or should be set to 'time of day'.


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