FS700 for Green Screen help... please!

R

roro20

Well-known member
We have shot a ton with our FS700 but not alot of green screen. Here are a couple frame grabs of a test shot that we had done. It (example 1) was recorded externally via SDI to a Samurai (ProRes422HQ), however there seems to be a white edge (right side of neck and sleeve especially) around alot of the talent which is wreaking havoc on the final key. The white edge is present on the AVCHD footage recorded to the SD card, as well.

After simply selecting the screen color in keylight (example #2), now not only is the grayish edge visible, but the edges are extremely jaggy. Almost looks interlaced. It looks worse to me than keying SD DV footage.

There has to be a setting that I am missing here on the output of the 700. My rec settings are 1080P30 FX and the SDI is set to output 1080P. I know it's still only 8 bit output but this is just hideous. I've shot and keyed plenty on 8 bit 4:2:0 cams, even DSLR and it looked ALOT better. Anybody have any insight? I'd appreciate your input. Thanks!
Green.jpgKey.jpg
 
Hi, I'm not an FS700 owner or professional by any means, but is it possible the "detail" and/or "aperture" settings were on? These will add white halos around contrasty edges.
 
What distance between this man and green screen ? ... I think it have to be as big as possible .. and don't illuminate it so much ... maybe this will help ( I'm not sure, but .. who knows ? :) )
 
Are those images 1:1 or scaled down, can you post an original frame? It looks more like a keying workflow issue. I'm guessing that the keying software has done a spill removal with grey and made the spill grey. You'll be wanting to key off the 4:2:2 footage if at all possible.

It should be fairly easy to sort those edges out though, depending on what software you're using. You should get good results from the 700.

cheers
Paul
 
Talent is around 10' in front of the screen. The original images I uploaded were 1:1 original frame grabs of the 4:2:2 footage, but I think DVXUSER scaled them down. Our keying workflow I believe is just fine. for this example I simply selected the screen color in keylight to show an exagerated version of the problem... that's the only keying adjustment made for this example. I havent made any spill or edge adjustments at all.

But the problem I am having lies in the whitish gray line that is around the talent in certain areas- including the original footage if you look closely. Because that seems to be throwing keylight off when I do go to make the adjustments to the key.

Thanks for your input!
 
Quick fix: Duplicate the track and do a track matte to separate the foreground and the key. Then shift the key with position adjustment.
 
Thanks @ericjurg- I know how to fix it to make it work. My question is what am I doing wrong so I can eliminate this. It seems to be a color sampling issue, I just didnt know if this was a common problem with FS700 green screen footage. Like I said before, the majority of my work is non-green screen. Although I have worked with green screen quite alot before on other cams and have never seen this issue- even 4:2:0 dslr stuff shot on green screen does not have this artifact. Thanks again...
 
I'm looking at the talent's hair and it looks backlit. YOu may be getting a back light halo, even if you don't intend to back light, if you screen lighting is spilling forward at all. Barn door your green screen lights to avoid forward spill.
 
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