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Compressor outputting darker clips

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Jacob Chase
Compressor outputting darker clips
on Jan 26, 2014 at 9:09:31 pm


I apologize in advance for the exhaustive posting.

We have recently wrapped production on a commercial shoot with two Canon 5D Mk III cameras, and we're now beginning post in-house.

Our workflow is as such:
- DP fills up CF card (SanDisk Extreme) on set. Hands off to DIT.
- DIT takes CF card, copies to hard drives, checks for QC.
- AE receives hard drive/CF cards, checks against cards to ensure everything was copied over.
- The clips are dropped into Compressor from hard drives & encoded to ProRes 422 HQ onto the server.
- AE brings the assets into FCP (7.0.3) & organizes for editor. Syncs audio. Begins pulling selects.

So while pulling selects (I'm the AE) we noticed what looks like an odd shift in brightness. At first I thought it was the DP adjusting ISO settings, as we primarily shoot documentaries and this is not uncommon to see. But after checking the source files (and asking the DP myself) it became clear that this was not the case. And they weren't just darker, the contrast also seemed boosted. It's as if the gamma had been tweaked.

I do not believe this is a monitor calibration issue because:
1) The anomaly does not apply to the whole clip, as I've stated. It's an intermittent thing. And...
2) We're seeing this happen through an AJA KONA card as well, not just on the standard computer monitors.

So then we thought it was a problem with the camera itself. We've been using the Mk III since its release and never had this issue. However we had just purchased a second camera before this shoot. Maybe we were sold a faulty product? Likely not, considering footage from BOTH cameras is having the same issue. Also, both cameras are on firmware 1.1.2, and a quick Google search tells me the 5d Mk III is currently on firmware 2.3.1. Could that be it? Is this a known issue?

I also have a hard time believing the issue lies in the CF cards. Again, we have used these cards before and never had any issues. I know cards go bad, but all 8-10 at once? I've also made sure the DP/DIT is formatting the cards within the camera, and not on a computer level, as I've heard that can cause issues.

I've tried re-encoding in Compressor multiple times and wielded the same results time and time again. I tried Episode, same thing. BUT it seems Adobe Media Encoder does NOT output ProRes 422 HQ with this issue. Everything looks fine. The only problem with AME is it seems to alter the timecode, leading to slight IN/OUT point alterations when reconnecting the media in FCP. This could be an issue as we've already done some editing.

We have another commercial shoot starting this week in France and we want to be sure the problem isn't rooted in the camera or the cards, seeing as we were planning on using the exact same equipment. It would be very much reassuring if anyone could shed some light on this dilemma. Has anyone else experienced this? Again, we've used this exact workflow for years with no problems.

Helpful Information:

2 x 2.26 GHz Quad-Core Intel Xeon

Final Cut Pro 7.0.3
Compressor 3.5.3

Thank you!

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