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#57404
Pixnub
Keymaster

    @ Heidi Hendrickson

    In your case, the screen is more yellow than it is green.

    Yellow Hue  = 60
    Green Hue = 120
    Cyan Hue = 180

    Your Screen hue = 82 (22 from pure yellow and 38 from pure green)

    Most chroma key green screen are 120-140 in sRGB format (105-120 if Adobe RGB).  You really need the Hue to be between 100-140 for it to extract correctly.

    Some of it cold be the white balance is set a bit on the warm side. However, I don’t think in this case that would account for an entire screen color shift of this magnitude. You really need to get a different green screen. I recommend the westcott 5×12. That has a true chroma green color.

    See this screenshot. Look at the red and green channels. They are almost the same vale. Yellow is an equal mix of red and green. So with your screen, since the hue is almost yellow, the red channel is almost as high as the green channel.

    EZ Green Screen works on channel value separation and needs the green values to be a certain amount higher then the red and blue channels.

    The reason it is cleared outside of the subject a given radius away is because that is from the remove area outside of screen setting which is removing it. However, that won’t remove all the way to the subject.

    I wish I had a better answer. however, these will need some manual work.  I recommend a different screen for the next job.

    You can use the same technique that I told Scott. After extraction, select the mask and run a levels on it.  Then push the left slider to the right. until the screen is removed. This will make for hard edges, but I don’t have any better suggestions.  So that is why it is important to correct the issue in the setup and get a better screen that is actually chroma green.

    • This reply was modified 1 year, 6 months ago by Pixnub.
    • This reply was modified 1 year, 6 months ago by Pixnub.