4 Replies Latest reply on Feb 13, 2014 11:12 AM by Dave LaRonde

    Having trouble with artifacts in my greenscreen composition




      I'm using Premeire and After Effec ts CS6. I used Keylight 1.2. The key looked pretty good and I didn't noticve any problems. I then saved the file, opened up premiere and used Adobe Dynamic Link to pull the footage from my After Effects composition. Everything looked fine initially, but after saving, quiting, and opening the project up a few times, I started to notice artifacts in my project. I opened up the original AE file and noticed that they were there too. I have linked some pictures for examples. I'm kind of at a loss as to what happened or how to fix it. Any suggestions would be awesome. Thanks!


      Screen Shot 2014-02-13 at 10.07.41 AM (2).pngScreen Shot 2014-02-13 at 10.08.09 AM (2).png

        • 2. Re: Having trouble with artifacts in my greenscreen composition
          Mylenium Most Valuable Participant

          Flush the disk cache.



          • 3. Re: Having trouble with artifacts in my greenscreen composition
            BizAssure Level 1

            Additional Information:


            After Effects V.

            Premeiere V. 7.2.1 (4)


            Operating System: OS X 10.9.1 (13B42)

            Processor: 2.8 GHz Intel Core i7

            Memory: 16 GB 1333 MHz DDR3

            Graphics: AMD Radeon HD 6770M 512 MB


            Quicktime: V. 10.3 (727.1)


            Source footage - Filmed on a Canon 60D

            23.976 fps, 1280x720 Not sure of the native codec

            • 4. Re: Having trouble with artifacts in my greenscreen composition
              Dave LaRonde Level 6

              It's too bad it was shot on a DSLR; they STINK at precise color reproduction.  Oh, it's good enough to fool the human eye, but not a computer.  It's not the imaging chip that's to blame, but rather the codec in which that stuff is recorded.


              But if your main complaint is with noise in the blacks -- a common problem with Keylight -- I use two layers.  First, I pull a good key using Keylight, and I go by the Status setting: white at the core, grey on the edges, don't worry about the green tinges in the white.  The key is right.  I set it to Final Result.  I don't CARE if it looks a bit noisy: I know it's right.


              Then I duplicate the layer, and reset Keylight.  This time I go for spill suppression on the lower of the two layers.  I know that I have it when the chroma key background goes gray, and status shows me that Keylight isn't creating any transparency: it's totally white.  It's also very tricky to get to that point.


              Then I use the upper layer as an Alpha Matte for the lower layer.  Voila!  A nice-looking key with no noise.  If there is a spot with fast motion, I look at the blurred edges for any of the chroma key color.  If I see it, I tweak Keylight on the lower layer.


              If the edges don't look very good, I tweak the Keylight settings on the upper layer.



              You don't often find a simple, one-click-and-you're-done solution to keying.  It often requires masking, and a whole boatload of layers to build the entire image before you're ready to say, "Now, that's a good-looking key."