The method I just posted does not despill directly.  It gives you the amount of green that despilling would remove from the image.  You could set this layer to "Subtract" to remove that green from the original image.

Also I wouldn't use the Darker Color blend mode for despill.  Darker Color works based on the luminance of the pixel where as Darken works on a per channel basis.  The results generally won't be any different (unless you've modified the R/B channels as well) but I consider Darken to be best practice.

On Tue, Apr 2, 2013 at 1:46 AM, Robert Kjettrup <robert@stvmayday.dk> wrote:

Hi Darby

On my last two keying jobs i used your tip with channel mixer set to GR:-50, GG:0, GB:-50 and setting the layer to DarkerColor with great results, much better than the native despill in Keylight, thanks for that tip. :-)

Just tried this other channelmixer usage, and that i can also see as a good alternative, but it is a bit harsher in its despill in darker areas, more like the default despill in keylight. I setup the layer with the channelmixer effect as a difference blending mode. Correct? it looks correct :-)

- Robert

2013/4/2 Darby Edelen <dedelen@gmail.com>

A different Channel Mixer setup can pull a good spill matte.  In the case of a straight up average R+B spill suppression you'd zero out all the fields in Channel Mixer and enter for the Green channels:

Green-Red: -50

Green-Green: 100

Green-Blue: -50

Then the green channel will contain the spill matte.  Shift Channels can move that information around to use for either an Alpha or Luma matte.  Sure it's not as easy as having a one stop solution, but it's not too much of a pain either :)

On Mon, Apr 1, 2013 at 6:31 PM, Chris Zwar <chris@chriszwar.com> wrote:

Thanks for these links, I enjoyed the videos.  What a shame the native Cinegobs plugins are Windows only, it would be nice to be able to pull a spill-matte so easily on a Mac.

-Chris

On 10/03/2013, at 9:55 AM, Daniel Griffin <dagrial@gmail.com> wrote:

I've found the Green Limited by the Average of Red and Blue technique very useful and has given me the best spill suppression results so far:

http://ae.tutsplus.com/tutorials/workflow/advanced-spill-suppression-methods/

Daniel Griffin
www.kubikafilms.com

2013/3/9 Chris Meyer <chris@crishdesign.com>

Many thanks, and absolutely nothing personal, but I have a client confidentiality issue on these particular shots that I don't want to tread anywhere near.

 - Chris

________________________________________________
Chris Meyer | Crish Design
http://www.crishdesign.com

On Mar 9, 2013, at 12:48 PM, Andrew Embury wrote:

I'd love to have a crack at that too Chris!

Cheers. 

- Andrew

On 2013-03-09, at 2:13 PM, Jack Tunnicliffe <jack@javapost.ca> wrote:

Chris:

Can you send me a frame. I'd be curious if I could focus in on the area you're talking about. Maybe a screen grab with some arrows or pointers showing me the area as well as a frame of the original, like a tiff.

Jack Tunnicliffe

Java Post Production

402, 2206 Dewdney ave.

Regina, SK

Canada

S4R 1H3

P. 306-777-0150

cell. 306-536-4321

www.javapost.ca

______________

On Mar 9, 2013, at 10:36 AM, Chris Meyer <chris@crishdesign.com> wrote:

I have found the edge decontamination of Refine Matte very useful in some situations, but not all. The two shots causing me grief this week have 1) a large amount of spill across the bare shoulder/upper arm of an actress, and 2) more than half way across the shirt on the back of an actor who is turning. Unfortunately, when I increase the decontamination range on Refine Matte, it does something very ugly to the color channel information - what looks like a edge pixel repeat, instead of a simple removing of color from otherwise detailed pixels that I wish to keep. 

 - Chris

________________________________________________
Chris Meyer | Crish Design
http://www.crishdesign.com

On Mar 9, 2013, at 12:41 AM, Todd Kopriva wrote:

Check out the Refine Matte effect for the motion blur color decontamination.

On Friday, March 8, 2013, Chris Zwar wrote:

I don't know if it's technically 'spill', but motion blur is the tricky thing to deal with when keying.  If the key isn't set up well then you can end up with footage that looks like it has a spill problem in moving areas - actually the screen is showing through semi-transparent regions.  

--
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Todd Kopriva
1510 E Alder St
Seattle, WA 98122
(206)437-2296
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"Ultimately, all knowledge is self-knowledge."
   - Bruce Lee