DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   All Things Audio (https://www.dvinfo.net/forum/all-things-audio/)
-   -   Dual Recording (https://www.dvinfo.net/forum/all-things-audio/55523-dual-recording.html)

Spike Spiegel December 4th, 2005 09:13 PM

Dual Recording
 
I am looking for a device to wirelessly transmit TC from my primary camera into my field recorder. A wired connection is not possible in this application. Does anybody know of a company that makes these? Where can I find them? Are they reliable?

Cheers

Spike Spiegel December 6th, 2005 03:35 PM

Nobody knows anything about any of this? Does such a device exist or am I going to have to invent one, patent it and make my millions that way?

Douglas Spotted Eagle December 6th, 2005 03:45 PM

Other than logging assistants, I'm not aware of anything that can do something like this. Maybe one of the logging assistants could be modified. Given that tape is nearly dead...I doubt you'd make millions. :-)

Bob Grant December 6th, 2005 05:04 PM

I have seen such a system at a trade show but pretty expensive. Then again if you're using LTC it's only audio so any audio RF device would work OK.
Thing is there's also a few precision TC generators that go onto cameras thus avoiding cables and RF links, they're so good they drift less than a frame per month.

Spike Spiegel December 6th, 2005 06:17 PM

All I am looking for is something to plug into our camera guy's XL2 and send the timecode that it is generating, no matter the form, to my 744T.

Wouldn't it basically be a modified Lav system meant to send TC rather than audio?

Here is my situation:

Our show is a travel documentary set in several different countries. The sound guy cannot be hooked up to the camera guy as the various shooting situations simply would not allow for this.

I can choose to neglect the time code option or simply jam sync the 744t, but I am trying to make post just that much easier and not have the editors having to worry about syncing up audio as well as all the other things they have to do.

If anyone has an alternative method to my situation please let me know.

Cheers,
SS

Jay Massengill December 6th, 2005 08:58 PM

I would use free-run time-of-day timecode on both devices, jammed as needed to maintain accuracy. Or use the highly accurate boxes that Bob mentioned such as the Ambient Lockit box on both devices so that drift is minimized.
With free-run code, it doesn't matter when each device is started or stopped and if your sound person needs to roll some wild segments you can't end up with duplicate but not-in-sync timecode numbers.
There's resistance from the editing community regarding free-run code, but from what I've heard that comes mainly because the interns that are capturing footage into the Avid at night have to make several mouse clicks each time there's a jump in the TC. For most people capturing their own footage on other NLE's, free-run isn't a problem and just makes perfect sense to me.

Spike Spiegel December 6th, 2005 10:29 PM

That is true, I didn't think of TOD.

BTW I love the $1k+ price tag on the TC generator... would I need a controller for the Ambient Lockit, or does it generate on its own?

Robert Mann Z. December 6th, 2005 10:53 PM

we use the TOD in our setup and use edius to do automatic syncs, i'm sure most nles have this feature, there times where for one reason or another we are off by a frame or two but in the end it save oodles of post time...

Spike Spiegel December 7th, 2005 02:05 AM

TOD seems to make the most sense thus far. I don't know why I didn't think of that earlier, I could have saved myself on major headache. Thanks guys for all the input. Now I am curious about these TC generators. Would I need one per TC accepting device? How exactly do they work?

Jay Massengill December 7th, 2005 08:16 AM

The Lockit is a highly accurate TC, video sync and wordclock generator and one goes on each device. Jam them once or twice a day and they should hold sync with much less drift than the devices themselves.
If you're lucky and your devices hold together on their own, you could do without any external devices. You might have to jam them more often but it would still work well enough to keep close track of the relationship between video and audio material. You could test this ahead of time and see how close they do. For example I did a shoot the other day and two of my cameras drifted less than one frame over a 1 hour take.

http://www.ambientaudio.com/products/timecode.html

B&H is selling them for $1184 each, so I'd definitely be hoping that your devices don't drift much on their own.

http://www.bhphotovideo.com/bnh/cont...ist&sku=327178

Spike Spiegel December 7th, 2005 12:48 PM

I think I am going to do a few tests with TOD and see how that works out. Although I don't know if I want to spend the 1100 x 3 devices just to make the editors job slightly easier.

Steve House December 7th, 2005 01:37 PM

Quote:

Originally Posted by Spike Spiegel
I think I am going to do a few tests with TOD and see how that works out. Although I don't know if I want to spend the 1100 x 3 devices just to make the editors job slightly easier.

The Lockit boxes apparently do serve as identical twin master devices for external sync that can slave both the camera and recorder to them as accurately as if they were all hardwired to the same master. Of course, whether that will work assumes your camera and recorder HAVE genlock or external TC input capability in the first place. You didn't mention what camera and recorder you're using or your budget but the only camera I'm aware of in the sub-10 kilobuck price range that has TC input and genlock is the new Canon XLH1. Absent the required inputs, most digital devices today have clocks accurate enough that they should keep the same time pretty closely over most normal shot lengths. (Lockit claims accuracy of 1 frame per month!!!!) By setting the internal clocks to TOD or free-run and using an old-fashioned clapper to slate each take you should stay pretty close, especially if you take care to record the audio at the 48kHz sample rate of DV instead of the 44.1 kHz sample rate common to digital audio (thus avoiding potential timing errors caused by having to resample the audio when you import it into your NLE.) One way to fix drift caused by slight differences in clock rates between camera and recorder during longer shots is to record both a head slate and a tail slate on the set for each take. Line up the head slates in the editor and the tail slates should also fall into alignment. If they don't, use the "time stretch without pitch change" tool found in most better NLEs to slightly tweak the tail of the audio until both audio slates line up to their corresponding video frames.

Just made an interesting discovery in the Sound Devices 744T recorder manual. According to their manual, its time code circuitry is by Ambient, the manufacturer of the Lockit boxes, and has the same accuracy as a Lockit when tuned to the Ambient Master Controller (just as you have to do with the Lockits). So if you choose that as your audio device, you'd only need a Lockit on the camera instead of 2 to be in business.

Dietmar Zonewicz January 7th, 2006 03:29 AM

I've got a question about using the Lockit modules:

I knew them well using them on Digibeta and DVCPRO, but what about using them with usual DV camcorders, like the DVX100? I was told it might be possible to record the TC on one of the audio tracks. But how to tell the NLE (FCP) that one of this tracks is the TC and how to synchronise it with other video sources?

dietmar


All times are GMT -6. The time now is 07:12 PM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network