9 Replies Latest reply on Feb 17, 2010 2:46 PM by Aaron - DCMC Productions

    Refining Keying in CS4

    Aaron - DCMC Productions

      Hey Guys,


      Recently I have begun using a green screen for some productions for my video produciton company, and I have been practicing and trying to figure out how to perfect the technique before setting out and doing it, as I have people asking me about it for a job right now.


      Anyway, here is the link to one of m videos, I am trying to fix it up a bit, wondering if anyone had any suggestions, thanks.





        • 1. Re: Refining Keying in CS4
          Matt Petersen Level 3

          actually as in-Premiere keys go, I think that's not too bad. Most serious keyers on this forum go out to AE for Keylight or the big one, Primatte.


          The only thing I'd say is your edges are a bit harsh. try dialling in some edge smoothing.


          I'm not sure of your setup, but all I'd say is: light your screen carefully (OnLocation is awesome for this), light your talent just as carefully, use the highest quality format you can in your camera, and don't be afraid to try the 'other' keys in Premiere (I've settled on "Colour Key" for HDV work).


          one of the TOUGHEST calls in key work is knowing when to use, and when not to use, a key shot. sometimes a 'practical' is simply a more economical and believable option!


          lookin good.



          • 2. Re: Refining Keying in CS4
            shooternz Level 6

            Here is my basic  input for you.


            Use some back light.


            It can be actual light units but also its nice and simple to put two large vertical reflectors  6x4 foam board to give the feel of light on each edge of the person.


            These are what I call 3/4 back lights.


            All backlight helps with keying and looks much more natural. it stops the hard cutout look that you have in your example.


            I will try and post a couple of pix up what this modelling light  looks like.

            1 person found this helpful
            • 3. Re: Refining Keying in CS4
              shooternz Level 6

              examples of key work









              • 4. Re: Refining Keying in CS4
                Matt Petersen Level 3

                some awesome examples there.


                some people suggest the use of a "hay" coloured gel on those backlights (to counter fringing). I've never tried it, but worth knowing.



                • 5. Re: Refining Keying in CS4
                  shooternz Level 6

                  I often will color my backlights (and my key lights for that matter.)


                  The object is to make the key fit with the feel of the bg and a little straw or 1/4 85 can also kill green /blue spill.




                  Another sample





                  • 6. Re: Refining Keying in CS4
                    Level 4



                    I think that looks great !   And you could probably make it a little nicer looking with some minor lighting adjustments...but only if its in your budget etc.


                    Your key on camera left is a little behind your subject ( fear of lighting the screen maybe with spill ) and I would move the key around more to the front and use a flag to keep it off the screen....   4x8 sheets of black and white foam core work well for this if you don't have solids (flags)....black side to screen...

                    There are black and black foam core sheets if you can get them...black and white is more common and work great...spring clip together ....


                    Maybe use some diffusion on that key...like opal tough frost ( which is very slight diffusion and about a 1/4- 1/2 stop loss only ) will help light wrap around your subject a little bit...will be less of a sharp shadow....   You can double up the diffusion ( two layers of opal tough frost ) if one is not enough


                    ( see Rosco or Lee for rolls of opal )  -- can use the opal in a frame or in a pinch use wood clothes pins and put on barn doors ...


                    Use a little fill on the camera right side....just a little....and also if you can get a light up there and in the back, I agree...some backlight would be nice...maybe like a "hair" light....just to separate your subject from the background a little bit....would look nice !


                    As far as the software and key stuff and blur for the edges, you've already got great suggestions above...


                    Good luck..



                    1 person found this helpful
                    • 7. Re: Refining Keying in CS4
                      Level 4



                      If you're worried about light kicks off the lenses of glasses, take lenses out...nobody will notice



                      • 9. Re: Refining Keying in CS4
                        Aaron - DCMC Productions Level 1

                        Thanks alot everyone, your input helped a tonne!