Thursday, October 29, 2020

[Avid-L2] Sony HDC-4300 4K live camera to switcher to KiPro recording Quadrant issue?

Production show a 4 camera shoot with Sony HDC-4300 cameras.  It was a full production truck with a switcher.  I don't know what kind of switcher at this point.  They did a live switch and isos.  The line and isos were recorded on KiPro recorders, don't know what model.  They recorded to SSD Cards that were offloaded between performances.  I'm told the KiPros recorded ProRes 422 UHD. 

The problem is that several of the isos and a think some of the cameras on the line cut have issues with the lower left quadrant.  When I heard this I figure there was some sort of quad link issue somewhere.  I don't know anything other than above but more will be revealed tomorrow.  According to the Post Producer who was in the truck during the shoot he thought he saw the issue after the first performance but had no time to check it because they had to offload the cards to make room for the second show.

According the the post producer the camera test files were with locked off shots that don't show the issue but when the camera is moving then the bottom left quadrant seems out of sync and off.  I haven't seen the footage so I can't tell more than this now.

My first thought was some quad link timing issue.  IIRC monitors have a window of tolerance for the quad link feeds but perhaps they are more forgiving than the KiPro recorders.  I figure they would have seen the issues in the control room line cut and camera monitors and fixed the problem so I can only assume everything in the control room looked okay while they were recording.  I think when the KiPros record they output an E to E signal so there is no confirmation head playback like in the tape days so maybe the recorders looked okay as they taped but on playback the problem arises. 

I google the camera and it's control unit and it has 4 SDI outputs so I'm assuming it outputs only quad link but It wasn't obvious from a quick peak at the sony pro site.  The HDC-4300 us described as an easy migration from HD to 4K so I'm thinking it may not offer the Dual Link or Single Link 4K feeds.

Bottom line is it must have looked okay in the control room for this not to be noticed during production and I can only think given the nature of the error showing up in the lower left quadrant that somewhere in the food chain quad link was involved.  Why a static shot would be okay but a moving shot shows the issue I'm not sure of.  Having not seen the footage I can't play along well.  I would think the timing of one of the quad links being off wouldn't show a quadrant out of sync, or the post producer described the lower left quadrant looking like it had interlace errors. 

I wonder if they had to convert the quadlink to single or dual link to record on the KiPros?

So many questions just wondering if anyone has any insight as to if I'm on the right track with thinking it's  quad link issue.  Could timing account for this?  How can it look okay in the control room and during recording but not on playback?

Scratching my head.


John Moore Barking Trout Productions Studio City, CA bigfish@pacbell.net

No comments:

Post a Comment