Chroma Key Face Line Problem

Randini wrote on 2/15/2010, 2:06 PM
I have a well lit green screen, use Chroma Blur and Chroma key. I watched many tutorials on the web and mask everything out. I'm 90% satisfied but can not for the life of me get out a slight green around the face. Here is a sample:
http://vildproductions.com/images/green_screen.jpg

Is there a video fx in Vegas that could help?

Thank you,
Randini

Comments

BudWzr wrote on 2/15/2010, 2:17 PM
Use color correction and adjust the green toward cyan or yellow either before or after masking.
farss wrote on 2/15/2010, 2:26 PM
"Is there a video fx in Vegas that could help?"

You could probably build something in Vegas or better yet buy Boris's Chroma keyer. I haven't tried that one myself but many do rave about it and it was on special at Digital Juice.

That said how much Chroma Blur did you use, it looks to me like you might have overdone it. You've lost fine detail in the key around the hair.

There seems to be quite a bit of green bleed in the original frame, how far from the screen was the subject?

Bob.
Randini wrote on 2/15/2010, 2:27 PM
Hello BudWzr, this is interesting. I'm not too skilled at color corrector. I see two many settings: Red, green, blue Midtones, red green, blue highlights, remove yellow cast. Then once I pick one I get three wheels (low, med, High) If I dabble with one it effects everything on the screen which includes my subject.

NOTE: I also see a Secondary color corrector

Thank you,
Randy
Randini wrote on 2/15/2010, 2:31 PM
Hi Farss,

Yes. I have heard that Boris is excellent I should check that out. Thanks for the link.

The Chroma blur I used medium but even if I bring that down it does not reduce that green around the face it just makes it more jagged.

I did not film this subject so I do now know how far away he was. I should ask him.
BudWzr wrote on 2/15/2010, 3:07 PM
Use the secondary color corrector. But like Bob asked, if the subject was too close too the green screen, that's probably the cause. It's a color "cast", not a bleed, so there's nothing behind it and you'll remove part of the head edge. Hahahaha, maybe you can fuzz the edge a little.
farss wrote on 2/15/2010, 3:21 PM
"I did not film this subject so I do now know how far away he was."

OH!

I've wasted countless unpaid hours trying to fix other peoples efforts at shooting green screen. If asked again I'm going to quote double what it'd cost for me to shoot it and post it. Strictly full payment in advance and no guarantee.

Looks to me like they had the talent almost hard up against the screen. There seems to be a hard edged shadow on the screen which is creating an outline that'll be a bear to key.

Feel free to email me a frame of it and I'll have a go but seriously I would not hold much hope of pulling a really good key from that. White hair is problematic over a screen.

One tip, don't try too hard for perfection in the key. Look at it over the intended background, some bleed between subject and background can give a better result that trying to get a perfect key upfront.

Bob.
Laurence wrote on 2/15/2010, 3:26 PM
I have both the Boris Chroma Key and the New Blue Video Essentials one. Of the two, I like the New Blue Video Essentials plugin better for most things. The feature in particular that you are looking for is called "choking". This feature allows you to subtrack a given amount away from the entire edge of the outline. Not a perfect solution, but it sure helps get rid of the worst of the halo.
JohnnyRoy wrote on 2/15/2010, 3:43 PM
The problem is that the Vegas keyer doesn't have spill suppression or a matte choker, both of which would help you in this case. As Lawrence said, the New Blue Video Essentials II Chroma Keyer might help you. It has both spill suppression and a matte choker. Download the trial and see and it won't break the bank if you decide to buy it.

~jr
Randini wrote on 2/15/2010, 8:51 PM
Great advice everyone thank you!

I want to try the New Blue Essentials II
I just installed the trial version on my PC but I am getting the following error:

Newblue Essentials II for Windows has not been totally installed:
Help/coloreq.wmv: This file contains invalid data. (error 11FD)

Newblue's forum had no help for this and I even did a serach on Google and was not successful.

Any ideas?
Rory Cooper wrote on 2/15/2010, 9:45 PM
If you make garbage matt this will allow you to color correct on your clip by crunching the green without affecting the chroma key

As the alpha matt is an exact matt of your key,the correction done on the second clip will not affect the original key

NewBlue chroma key gets a big thumbs up from me

What media/format are you editing??? Progressive etc, as this will also have a bearing on the results you are getting
Randini wrote on 2/16/2010, 12:06 AM
Hi XFX,

I'm awaiting tech help from NewBlue and can't wait to try out their Chroma. I am rendering progressive.

Cheers,
Randini
farss wrote on 2/16/2010, 12:28 AM
You can add a CC FX after the CK FX and it should only affect whatever the key retains, no need to do anything complex.

I did take the sample you provided into V9 to have a stab at it.
The good news is the screen reads pure green on the scopes so I just used the Pure Green preset to set the angle of the key. So far so good.
I added a track of solid red at the bottom of the T/L and started to adjust the in/out levels. Then I really noticed the big problem. The gents right arm has heaps of green bleed, must have been a very shiny fabric. Ignoring that I could get a pretty good key on the hair, preserved more detail than you'd managed. The face was OK too but the coat remained a problemo.
I suspect to take a good shot at this with any keyer you're going to have to split the problem up using masks and use different settings for each problem area.

Bob.

Al Min wrote on 2/17/2010, 10:12 AM
Rory, can you point me to a tutorial that shows how to create and apply a garbage matte? I have New Blue II, but like many others want to improve what I am doing. Any help you can give me would be much appreciated.
HyperMedia wrote on 2/17/2010, 10:31 AM
Boris Red Chroma Keyer also good for Green Screen stills. It knock out the green screen in the background with one click. If the Boris CK doesn't do the complete job. I add the Matte Cleanup next.

Remember, Boris Red have additional 11 different key function to get the job done. Most people doesn't know how to use all the different keyers the Red supply.

Furthermore,when using Boris Red I'd swap out mulitple shots using that same save Boris CK template with minor tweeks to the different clips. That save so much time when using 50 to 300 CK clips.

That's why I use Boris Red over Combustion 3, Vegas and Affect Effects. But in Affect Effect I know you can replace the clips and those settings will be there. But you would still have to tweek a little bit more. With Vegas and Combustion you don't get those same results.
BudWzr wrote on 2/17/2010, 2:42 PM
Oh, that's a STILL? Take it into Photoshop and throw an additive selection mask, and leave a transparent background. Save as PNG.