SDI projection - sync/field dominance(?) issue

[Matt Chan]

This is off topic for an audio forum, but here goes:

We are seeing some sort of sync error when we project from tapes we received for a screening.

Christie Roadster S6 is being fed an SDI signal from Digi-Beta deck. We get occasional green lines flashing across the screen and they appear to be horizontal sync errors. Now here's where it gets confusing:

- Glitches are repeatable and appear in the same spots on both D-Beta tapes (output from FCPro at our facility) and analog Beta SP tapes (created at client's facility).
- Glitches only appear using SDI output from D-Beta deck, not on the component output
- Glitches do not appear on an SDI monitor using the same deck
- Deck is locked to blackburst and I have tried swapping them out.

The tapes in question were created from FCPro sequences at a post-secondary school. So who knows what really goes on there. My instincts tell me that this is either a field dominance issue or a gen-lock issue during their digitization. We have only seen this happen once before, on another questionable tape about a year ago. But we use this deck heavily for dig'ing mix picture, and running private digital screenings and there haven't been any other problems.

Any advice or suggestions would be much appreciated.

Cheers,
Matt

[Eric L]

Use the component out for the screening or remake the tapes, whichever is easier and acceptable. It is a tape error that you can not fix after the fact. The fact that the glitch is on both Digi and SP means the FCP project is messed up and needs to be examined, paying special attention to those areas.

[Matt Chan]

thanks eric,

that's exactly what we did....

the sequence for the output was an assembly of 14 student projects so there could be any number of problems with it.