3 Replies Latest reply on Jan 9, 2013 10:23 AM by Fuzzy Barsik

    Green Screen keying issues

    dh91 Level 1

      Hey guys.

       

      I am keying some footage sent my way for VFX'ing. The key by default turns out pretty darn good accept for regions around the hair. I get this weird purple colored noise along the hair edge and in the eye. (eye is easily correctable with masks I know).

       

      Screen Shot 2013-01-09 at 10.28.48 AM.png

      Original

      Screen Shot 2013-01-09 at 10.27.48 AM.png

      Screen Shot 2013-01-09 at 10.27.14 AM.png

       

      It may be hidden by various fog effects, but i'm still paranoid about it. If I change the replace method from soft light to hard light the unwanted effects sort of clump together tightly around the edges (and leave the eye altogether).

       

      Aside from some masking work, are there any suggestions for keylight settings I may want to consider first?

       

      Thanks!

      Dan

        • 1. Re: Green Screen keying issues
          Rick Gerard Adobe Community Professional & MVP

          The noise is because you haven't tweaked the settings enough. I'd use a hold out matte for the eyes and other problematic areas where reflections and spill foul up the key. That's standard practice.

           

          It also looks to me like your source footage is compressed. The less the compression the better the key. You might try transcoding the footage to a 10 bit production codec before keying and applying some noise reduction. Then it's just a matter of cleaning up the key using matte tools or the settings in Keylight.

           

          You should also consider some light wrap. I don't see any in your scenes. Light wrap will hide a multitude of problems and make the shots much more believable.

          1 person found this helpful
          • 2. Re: Green Screen keying issues
            dh91 Level 1

            Thanks Rick for the tips. This should help quite a bit.

             

            1 more question.. I posted here some time ago and asked if transcoding the footage to an uncompressed format would help with a color key, but the response I got was something along the lines of "you can't create more color information from no color information".

             

            Would for sure help to transcode to something like prores or animation before attempting the key? The original files are .MTS, and exist as such in the Premiere timeline.

             

            Thanks for your help,

            Dan

            • 3. Re: Green Screen keying issues
              Fuzzy Barsik Level 4

              Check out this discussion, run your own tests and judge on your own.

              1 person found this helpful