Feeding Audio to Red & Preserving TC

[Tommy]

If a 744T recording 24bit 48kHz with 29.97 NDF TOD timecode feeds a 2 track master mix to a Red camera recording 23.98fps with TOD timecode... is the audio timecode preserved or does it get imprinted with the camera timecode? Thanks, Tommy

[Mike Paul]

Unless the two devices' (Red & 744t) timecodes are somehow connected, then no, there will be no relationship between the two.

You would want to jam timecode from the Red (TOD) to the 744t (Free Run), or from the 744t (TOD) to the Red (Jam TC).

You can run the 744t at 29.97ND with the Red at 23.976ND, but I would advise using and Ambient Lockit or Denecke SBT to cross-jam the codes.

Or, run them both at 23.976ND if you'll be editing at 23.98

[Cail Young]

Originally Posted by Mike Paul

You can run the 744t at 29.97ND with the Red at 23.976ND, but I would advise using and Ambient Lockit or Denecke SBT to cross-jam the codes.

Have you tested the RED ONE's internal cross-jam and cross-gen routines?

[Mike Paul]

I haven't tested the cross-jam functionality yet. It's a neat feature, but I don't think many people are even aware of it or what it does. Cross jamming has been a way to get around the limitations of NLE editing systems when dealing with HD material, but with improvements in available firmware and hardware of these systems, we may see the need to cross jam become less and less.

Let's say, for the sake of argument, that the Red One's cross-jam function works correctly and the Red's internal TC clock is stable enough over time (and temperature) to hold frame accurate sync over a period of several hours. The only question I would have is: What happens when the Red One is powered down for any reason? What happens to the TC?

In most cameras, even if the clock is still running while the unit itself is turned off, the stability and accuracy of that clock is not as good as when the camera is on. This generally results in a frame (or two or three) offset in the timecodes once the camera is powered back up and filming continues. Power down the camera a few times over several hours, and the offset is magnified. This generally results in an angry phone call from Post to the Production Mixer with a "Why did you screw up our timecode" message, when it's really not their fault.

In order to avoid getting that call, most mixers would either:

a) Make sure to re-jam TC every time the camera is power cycled (difficult to do if the Camera Dept. neglects to notify you of a power down).

or

b) Use an external TC device to feed TC to the camera that is independent of the camera's power source (i.e., Lockit, etc.).

Being a Sound house, I don't really have easy access to a Red to test the functionality, but if someone wants to loan me one for a day or two..........:)

[J. Eric Camp]

Everything Mike says is correct.

The camera does not hold solid TC through a power cycle. If you are simply jamming the devices and expecting to walk away then expect to jam the red every-time it power cycles.

I personally like to simply keep a lockit box attached and then there is one less thing for everyone to worry about.