On a shoot! Dropped frames when capturing in FCP using Blackmagic

[Asger Lindgaard]

I'm doing a shoot with two identical cameras and we need the footage from both to be live captured into fcp using a blackmagic card.
On one camera it works fine, when outputting both via SDI 1080p and 720p but on the other camera the footage is blinking and frames are dropped when capturing.

We've tested all SDI outputs and cables on a regular monitor, so that's not where the problem is.

Anyone have a suggestion as to what the problem might be? Something I overlooked?

Cameras are Build 17, project settings are 25fps, 4k 16:9, 50hz, no assists or frameguides enabled.

Thanks!

 

[Nick Shaw]

Have you tried looping the signal through the monitor and into the Blackmagic. Most HDSDI monitors re-clock the looped signal, and the Blackmagic may well be able to capture it then.

 

[Asger Lindgaard]

Yes, we tried that too.
Works fine with one camera, not the other.

 

[Virgil Kastrup]

Are you capturing to two blackmagic cards, one for each cam? You've tried the working cam on both cards, if that is the case?
*Edit*
I may be misunderstanding the procedure.
Are capturing as you shoot or after you're done?

 

[Asger Lindgaard]

We are capturing the footage from one cam into one mac, and the footage from the other camera into another mac with its own blackmagic card. So it will be two separate configurations.

We will be live capturing, so the on set editor will be capturing on the mac from action to cut.

So yes, we've tried the working and nonworking cam on both blackmagic cards. Same problem as before: one camera captures fine and one drops frames and can't be monitored in the fcp capture window without blinking.

 

[Cail Young]

Blackmagic Design out here in Australia measured out-of-spec jitter on the HD-SDI signal coming out of the ET breakout box on a RED ONE (did not have time to take it off and measure straight out of the port).

This may be your issue. Are both cameras running the same build version?