4 Replies Latest reply on Jun 17, 2008 2:59 PM by (Nic_Coe)

    Green Screen (keylight) problems

    Level 1
      I've got people in a car filmed in front of a green screen, and a 'superhero' flying alongside the car. When I use the Keylight filter to remove the green, it changes the colour of the superhero's costume. How can I change it so it removes the green screen, but doesn't change his costume's colours?

      See the comparison images below:

      Original footage:
      http://www.thepfjstudios.com.au/images/raw-footage.jpg

      After Keylight filter:
      http://www.thepfjstudios.com.au/images/keylight.jpg
        • 1. Re: Green Screen (keylight) problems
          Mylenium Most Valuable Participant
          Well, short answer (that you won't like): You should have thought of that before shooting and chosen different colors for the costume. They are simply to close to the green of the screen and the lighting of the scene is blown out, intensifying the problem. Still, not all is lost. I recommend you work on duplicate layers in a pre-comp that you use as matte for your source footage instead of keying directly. Increase the contrast by hue-shifting and oversaturating the colors of the suit, then combine it with your normal key for the face and rest of the scenery. Add more layers as you need them to get perfect Alpha for al lthe elements. Apply the pre-comp as an Alpha matte to the normal footage after that. Use Matte Choker, Simple Choker and Alpah Levels to do some finetuning. You may also need some rough masks in your pre-comp to clean up the edges of the different keys.

          Mylenium
          • 2. Re: Green Screen (keylight) problems
            Level 1
            Yeh, I wasn't at the filming for the days when they were using green screens. I was only there for the outdoor street scenes, which was the last day of filming, and they couldn't change it then. If I had known, I would've suggested maybe a red costume instead.

            I'll give all those a go - pre-comp, mattes, filters, and see how I go with that.

            Thanks Mylenium.
            • 3. Re: Green Screen (keylight) problems
              craulmedia Level 1
              hi,

              also try using multiple instances of "color key" for the different areas in the green, then apply keylight as seen in the laste A. Kramer tutorial. works well.

              the backdrop alwas should be placed farther away from the filmed object. green should be tight. DOP of camera helps to blur it out a bit. then it´s easier in post to get the results.
              • 4. Re: Green Screen (keylight) problems
                (Nic_Coe) Level 1
                Keylight has a setting (Screen Matte>Replace Method) that defaults to "soft colour", change this to " Replace with source" and the costume colour will not change.

                This will not solve any actual keying problems i.e colours too close but the suit will stay true to its original colour.