Transmitting Time Code Wirelessly

[silent-sam]

I am doing lots of run and gun gorilla style shoots........ there is a lot going on and the camera man can drop into record without every saying action.

Most of the time if your paying attention you can drop into record quick enough but sometimes you can't..... and I don't want to leave the hard disk recording running constantly

so to me the ultimate set up would be to have a portable recording device, that is independent from the camera, BUT to have that devices transport be controlled by the camera without having any wires connecting the device to the camera.

Because time code is audio, and you can record it to tape, or send it through an RCA cable- to me it seems like you could transmit through a standard wireless pack (with a modified cable)

Has anybody tried this? Is it possible to transmit time code wirelessly without having it drop out every couple seconds?.... Is it even possible to successfully lock time code wirelessly for even a couple seconds?

[Sound Sorcerer]

You can use a Comtek system connected to TC out off camera, also camera must be set to Rec-run, and if using a Sound Devices 7xxT recorder you can set it to initiate recording when incoming timecode starts running..
From SD 702T users guide:
"Ext TC-Auto Record:
The internal time code generator follows the external time code signal appearing at the time code input. When external code advances, the 702T enters record mode automatically. When the external code is stopped, the 702T generator pauses and recording is stopped. This is appropriate when dual system sound is used with video cameras set for Rec Run time code. The video camera will function as master time code and the recorder “transport” will follow the video camera transport.
Ext TC/cont-Auto Record:
The internal time code generator follows the external time code signal appearing at the time code input. When external code advances, the 702T enters record mode automatically. When the external code is stopped, the 702T generator pauses and recording is stopped. If the external time code is removed the internal generator continues to run to preserve continuous time code. Useful for time
code transmission over RF where RF “hits” may interrupt time code. This is appropriate when dual system sound is used with video cameras set for Rec Run time code. The video camera will function as master time code and the recorder will follow."

[Actualsizeaudio]

Originally Posted by silent-sam

)
Has anybody tried this? Is it possible to transmit time code wirelessly without having it drop out every couple seconds?.... Is it even possible to successfully lock time code wirelessly for even a couple seconds?

I've tried it, but it is really hard to get it to work right, you need the correct level and phase, and don't forget about latency in the wireless transmission.

Right now I am using a Zaxcom TRX 900 setup, which gets me TC and IFB audio back to my mixer bag it works great.

One thing you need to remember that people forget about. TC does NOT equal sync. TC when dealing with audio just tells you "where you are" not "how fast you are going". When the rolls (time between start of tape and stop of tape) are short this is not a big deal, but if the camera man rolls for a long time you really need to make sure your device is locked to either work clock or black burst. If you can not stay connected to the camera this way, there are a few options. One option is to use a Lockit box on your recorder AND the camera.

The other option is something I do a lot. I have an Ambient ACC501 master controller and a SD 744T. What I do when I want to make sure the crystal in my 744 is running close to the same speed as either my slate or a video camera or a truck master clock is I have the ACC501 "read" the speed of the device in question (by analyzing running TC), then have the ACC501 tune the crystal in the 744. Now, without clocking to word clock or black burst the 744 will run in very very close sync with any other recording device. As it stands now I can jam to the camera running time of day TC, and soon, zaxcom says my TRX900 will output TC out of the IFB100 TC out jack. Then I will be able to do exactly what it is you are looking to do.

[LX3]

Originally Posted by Sound Sorcerer

You can use a Comtek system connected to TC out off camera, also camera must be set to Rec-run, and if using a Sound Devices 7xxT recorder you can set it to initiate recording when incoming timecode starts running..

Ah, there you go, cleverer people than I have an answer for you!

[Actualsizeaudio]

BTW, I forgot to mention.

Both the 744T, and the Zaxcom TRX900 have a mode that sends the recorder into record when it sees TC advance. It then stops when TC stops moving forward. It works great on both devices. They will both freewheel for a while if there is a drop out, so the recorder doesn't start and stop all the time.

[Actualsizeaudio]

Originally Posted by Sound Sorcerer

You can use a Comtek system connected to TC out off camera, "

I've tried this with my comtek a couple of times and I have not gotten it to work. I figured the comtek compressed the signal too much for the 744 to hear it correctly. I've tried it a bunch of ways.

Maybe I'm not getting the level of the TC correct? Have you done this? I would love to know how you did it.

[Sound Sorcerer]

I've done this before for transcription purposes, feeding TC from camera using a Comtek 216 into my 702T on jam sync, but I always use manual recording as opposed to Auto-recording so I cant really tell if it works 100%. Maybe using a Sennheiser G2 would work best... And definitely if the budget permits the Zaxcom is a very elegant solution.

[Actualsizeaudio]

I like my zaxcom setup a lot, though it has not been without major bugs.

I believe ambient sells a small TC transmitter and receiver. I have been interested in these for quite a while.

Look at AMBIENT RECORDING

[aracu]

An easy, although imprecise, wireless method, to get the files close to where they need to be in post, is to have the timecode on all machines set to time of day. The Sound Devices 7xxt can be set to stamp the files with time of day.

[Actualsizeaudio]

Originally Posted by aracu

An easy, although imprecise, wireless method, to get the files close to where they need to be in post, is to have the timecode on all machines set to time of day. The Sound Devices 7xxt can be set to stamp the files with time of day.

The problem being that if the editor is expecting, or is use to using Rec Run TC he/she is going to be mad at the camera man. Time of Day TC is a bit harder to deal with in post, so giving the production house that hires you what they want is important.

Usually audio guys don't have the power to make a production roll Time of day TC while on set.

[taturana]

Originally Posted by Actualsizeaudio

The problem being that if the editor is expecting, or is use to using Rec Run TC he/she is going to be mad at the camera man. Time of Day TC is a bit harder to deal with in post, so giving the production house that hires you what they want is important.

Usually audio guys don't have the power to make a production roll Time of day TC while on set.

A couple of months i was asked to help a few people who shot their live show for a tv program to be aired just a week after with time of day tc.... what trouble they went to, it was hell in post... i would never recommend that...

[dkatz42]

I did exactly this in Zambia with a 744T and a Lectrosonics wireless rig carrying timecode from an HDCam. Actually we ended up with four channels of wireless (TC to the 744, lav to the 744 for simultaneous translation, safety audio back to the camera from the 744, camera to in-ear monitor for the camera guy.) It worked flawlessly; I just had to make sure the boom was pointing somewhere useful at all times in case the camera started rolling and the 744 started up. Combined with a good chunk of preroll and the free-run stuff, we didn't lose any audio in ten days of shooting.

Very nice for both of us to be untethered from the camera.

[huub]

Originally Posted by taturana

A couple of months i was asked to help a few people who shot their live show for a tv program to be aired just a week after with time of day tc.... what trouble they went to, it was hell in post... i would never recommend that...

I do not see the problem?
Studio shows, concerts and sports (any multicam shoot) are always recorded with time of day.. Certainly editors have no problem cutting this stuff...

Any eng cameras that want to lock to a multicam shoot just connect their camera to the trucks timecode, and keep it in free run for the rest of the day..

Well, I'm talking about time of day from 1 central tc generator, I guess you're talking about no central sync, right?

[aracu]

Well, I agree that it's not the ideal way to do it, but in a typical situation
where you arrive on a shoot which has not been organized sufficiantly to
synch in a more precise way, it is easier on post than not synching at all.

[Karl_Lohninger]

I have transmitted TC via wireless systems in all kinds of ways including Comteks (216 series) and they all worked except the Ambient system which as far as I know they get from one British company I forgot the name of. This thing in my hands never worked.

Denecke slates almost always have a Comtek velcroed on its backside - no problems there too. Of course the right level is important.

If you run RecRun of FreeRun doesn't matter. Syncing isn't really easier or more difficult with one or the other, just different. There should be no reason at all to make this 'hell in post'.

For all practical (but not theoretical) purposes, TC does mean sync.
'Lockit' boxes are way overused and make sense in rather rare circumstances. Often enough they produce more trouble than problem solving. As cameras are banged around mercilessly and cables pushed in all directions......green flashes anybody? I seen them and I'm not the only one ;)

TC is a nice invention and can make life easier but let's not forget that many many a Hollywood movies do not use TC or smart slates at all. Audible clapping is the unbeatable time-proven method.

For my first Bollywood production I prepared the usual way my playback setup for the big dance scenes with TC lists, count-ins, smart slates and what have you only to find out that the playback files i was getting were on a mono 1/4 inch real and the (super expensive) music director didn't want to hear a word about TimeCode.

Out came my Nagra - we shot for days with no notes no TC no nothing. What can I say, when I saw the movie everything was.....in sync :-)

Less really can be more and often the whole TC mess can be tracked to 'editors' who never learned their craft .....

Karl Lohninger
currently supervising 24H Berlin

[huub]

Well, all true..
I always try to be professional and do everything the right way (all video and worldclock coming from the same source, tc generator and daw tc synched to BB),
but on the occasions where I just used timecode, and eveything else internal (word, timecode reference), all was fine, and nobody complained..