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Using Magic Lantern => General Help Q&A => Duplicate Questions => Topic started by: heavygrafix on December 23, 2013, 09:39:51 AM

Title: Start Sync with two 5DIIIs
Post by: heavygrafix on December 23, 2013, 09:39:51 AM
Hi,

i am working on a Stereo 3D Rig with Convergence Sync and multiple crazy features for two 5DIIIs.
You´ll hear more bout this project in the future.
But what realy freaks me out, it the fact, that i cannot really sync the two camera with timecode or genlock.
If there where any option to input some audio, would be amazing. SMPTE for ML isn´t really working, isn´t it?

For now i got them start simultan, but with 1/8 to 1/4 of a frame difference.
I really want to get them closer together.
Luckily i can say, that the two models i owned are not running away from each other over the test time of 20 Minutes.
So for experimental usage i only have to sync up the start of recording.

i build a Y-cable Trigger, witch gives me a difference of 1/8 to 1/4 (max. 1/2 frame in worst few cases)

If you have any ideas, how to sync with more precision, like audio, light, heat or some Rasperri Pi, that all would be amazing!

Greetz.
Rudi
Title: Re: Start Sync with two 5DIIIs
Post by: MvM on December 23, 2013, 12:14:28 PM
Hi, please try the following:
1. Make a common power source, using two battery dummies from the external power connector, using on switch to power up the two cameras.
2. All settings in camera and on the optics must be identical.
3. Use identical CF and SD Cards, which are freshly formated and hold exactly the same content.
Then fire the cams with the remote.
This sort of worked with 5dmk2, their problem was that they drifted rapidly, atleast the two I had for trying this two years ago...
Basicly there seems to be quite a short "timewindow" for the camera to check for the command to start running, which means, the camera is not constantly checking for these commands but does so only 5 times per second or so. The timing of this window seems to be dependent of the startup timing of the cameras, therefor the synched startup procedures..

Good luck MvM ;D