Green Screen Footage messed up

[GoeroeMedia]

Hi there!

This is my first post here on the forum.
I hope you can help me with this weird problem we are having right now.

We already did a couple of shoots on the RED. Including green screen.
Last week we did another green screen shoot.

Everything worked out fine. Edited the footage in FCP. Transfered it with crimson to RedCine. Exported it to ProRess. Etc. etc. All of this on a brand new 8 core mac. 4 gb ram, Ati Graphics Card...

After exporting with RC to ProRess some weird artifacts appeared in the renders. It also appeared on other Codecs (RAW, JPEG2000 etc...)
The artifacts do not show up in RedCine itself.

This image shows SOME noise, but there are others where it's 10 times worse...

I tried to render the footage on a Macbook Pro with Nvidia Graphics. Same thing.

Then, I tried to render one sequence on a Quadcore PC with Nvdia Quadro 4600. Everything looked fine! But off course, this is not the way to do it.
Since I need to use the XML generated by Crimson to Roundtrip the files back to FCP.

Somewhere on the forum I read something about having this problem with ATI cards. But it also appeared on an Nvidia card...

Anybody has a clue what could cause this?

 

[Mark Allen]

Have you tried exporting out of redAlert (and then converting from there to some other codec)?

I don't have an answer - but it seems like a RedCine issue and I seem to remember a thread about something like this a while back.

 

[GoeroeMedia]

Yeah I also think it's a RedCine issue. But it's strange that it does work on a pc.

Haven't tried exporting from RedAlert. I will try that today.

I also tried exporting via RedLine in Crimson Workflow. That worked, except that for some reason it didn't apply the 709 color profile. So that's pretty useless as well.

My theory is that it has to do with some color value's. Maybe the values in my case are TO green and TO pink. But still, it works on the pc... so that doesn't explain it.

For now I have found a workaround. I lowered the saturation to about 0.800 en then increased (!) the green to still have some green information.
The renders now look a bit desaturated but I can fix that in the keying process.

 

[GoeroeMedia]

Ok just did a test on RedAlert.
That all worked fine.
No artifacts.

RedAlert uses the CPU for rendering and RedCine both CPU and GPU.

I still think it has something to do with the GPU...

But still, I can't use XML files with RedAlert.