5 Replies Latest reply on Jun 12, 2009 7:43 PM by Adolfo Rozenfeld

    Keylight - Inverting Alpha need assistance

    CantonVideoMan Level 1



      I have a project with a unique problem (for me anyway). I have included some screen shots to show what I'm up against. We have a video where we have an actors hand grabbing a green ball. The green ball needs to be transparent so we can animate a ball for the project. That's not an issue. However, due to a miscommunication this was supposed to be shot against a green screen as well (Only the ball is green). The final result I'm looking for is to show only the hand in the shot with all else being transparent.


      Using keylight I can get the hand to be transparent and all I really need to do is to INVERT the transparency. I tried using the "Invert Alpha effect (see last screen shot) but did not have the intended result. The remainder of the footage IS transparent, but the hand turns black. I'm sure this is simple but I  can't seem to figure out how to invert my aplha so that the hand becomes visible and all else is transparent.


      Any guidance would be appreciated.





      greenball 1.jpg


      Hand transparent using Keylight:


      greenball 2.jpg

      Result Adding the "INVERT ALPHA" effect:


      greenball 3.jpg