12 Replies Latest reply on Apr 30, 2009 11:43 PM by Rick Gerard

    Keying 16mm, a challenge to the adobe community

    luadke Level 1

      HI,

       

      I've been having some trouble with some 16mm keying. The footage is not all that sharp, and you can see (below) that i've had to sacrifice some of the edging in order to get rid of the blue. I have been using the standard 'color Key' tool in AE, I also tried experimenting with the image before keying it, like pushing up the blue beforehand. Does anybody have any good suggestion of how make this keying work. You can download a little bit of the footage on this link, the clip is uncompressed (about 35mb), please give it a go if you feel it can be done better - and tell me how you did it!

       

      Picture 6.png

      Picture 7.png

      Thank you

        • 1. Re: Keying 16mm, a challenge to the adobe community
          Mylenium Most Valuable Participant

          Just a few random thoughts before I go to bed:

           

          - Remove the grain.

           

          - Transpose the footage to a HLS color mode using Channel Combiner, then use the Hue channel as a matte by ways of Shift Channel. There is apparently a consistent amount of red in the foreground, that should provide some contrast that can be tweaked.

           

          - Similar to the previous, separate the channels, boost the red and green, recombine them in a pre-comp using Add blending mode, key out the rest or use one of the boosted channels as amatte adirectly.

           

          - RevisionFX Re:Fill to mend holes from keying.

           

          - Primatte keyer would do this in a wee.

           

          Mylenium

          1 person found this helpful
          • 2. Re: Keying 16mm, a challenge to the adobe community
            Rick Gerard Adobe Community Professional & MVP

            I don't think you'll ever pull this off with a standard color key. Keylight works fairly well. You're not going to get very far without doing something about the grain. It's very difficult to pull a really good key with such noisy footage. If the job is critical I'd go back to telecine and have the shot fixed there. They can do some marvelous things in the transfer to fix under exposed footage.

            1 person found this helpful
            • 3. Re: Keying 16mm, a challenge to the adobe community
              Todd_Kopriva Level 8

              I second the recommendation to use Keylight.

               

              There's a reason that the first paragraph of the documentation for the Color Key effect tells you to use Keylight instead.

              • 4. Re: Keying 16mm, a challenge to the adobe community
                Mylenium Most Valuable Participant

                Okay, downloaded your clip and gave it a spin. It's actually not as difficult as you made it sound and as it looked from the pictures. I agree with Rick and Todd - even that old bugger called Keylight would do a just fine job at keying this. The trick here is to bring the Black and White clipping of the matte very tight in (Black 20, White 35) to compensate for the lack of contrast in the luma and focus on the color information, then use clip rollback and despotting to get clean edges and fill the remaining holes from the grain. I also tried this with Primatte and as I said, it handles this without a problem as well. The main difference I noticed is, that using a deartifacting tool (built-in in Primatte), makes a huge difference for the sharpness of the edges. So consider using Magic Bullet Frames or similar tools you may have before applying the key or just get Primatte...

                 

                Mylenium

                • 5. Re: Keying 16mm, a challenge to the adobe community
                  luadke Level 1

                  Thanks for all the help,

                   

                  I did actualy start using Primatte on the shot, and your right there is a huge amount of control an trickery involved. Here is a compressed version of what i've been working on. I thought I had it but this really doesn't look good. Maybe I got carried away with the light wrap. This clip is with deartifacting set at 'other' and strength = 100%. You can see in the clip that I have a train running in the background this seems to make it quite difficult, because of the constant change in colour in the BG. Just looking at it now though i think the boy seems a bit too warm in comparison to the bg, but is also the lighting that is not soft enough. Please tell me where I'm going wrong with this. I can also upload the train layer if anyone wnats to have a go...

                   

                  Also I find it quite hard to judge how to move the train in comparison to the boy, and am quite limited with what i've got from it. Any suggestions on that?

                  • 6. Re: Keying 16mm, a challenge to the adobe community
                    Mylenium Most Valuable Participant

                    Mmh, yeah, of course the moving train gives it away. That's always going to be a problem. Naturally it just looks "flat" once you pull out with the camera. Perhaps a little artistic interpretation? You know, just using a vignette on the should could make a difference. Once you have that, you also have a good excuse to cover up the blue spill with a dark inner glow. If you want to lighten up the boy and make it less reddish/ warm, using a duplicate in Add blending mode with about 10% opacity could do a lot without killing detail. an alternate variation on the theme would be to make the boy the source of something that darkens the BG. You could use his matte shape on a horizontal Fractal Noise or treat it with Roughen Edges and Directional Blur. Give it a slight dark brownish tint, use Multiply or Overlay and again play with the opacity. Should provide some variation on the background that makes the boy look more like it's interacting with the train in some way....

                     

                    Mylenium

                    • 7. Re: Keying 16mm, a challenge to the adobe community
                      Rick Gerard Adobe Community Professional & MVP

                      I think the biggest giveaway is the background plate of the train. The parallax looks wrong the me and the movement should be down in the frame not up. Try changing the scale and movement of the BG plate. You may even want to introduce some camera shake to hide the little dip in the pullout and tilt in your foreground plate.

                       

                      Your spill and flashing fill on the subject is pretty good but could maybe use a wider range. Try darker when the BG is dark rather than lighter when there is a bunch of backlight. I also think that the edge of the key is a little too hard. Try softening a bit.

                       

                      The last piece of advice is to look at the shot cut into the rest of the scene. Sometimes I obsess with perfection too much and all of my tweaking is lost in the context of the scene. The hardest part of this business for me is to know when I'm done with a shot. I could tweak forever and still not be happy. The only way I know when I'm done is when I cut a shot into a scene and see how it plays.

                      • 8. Re: Keying 16mm, a challenge to the adobe community
                        luadke Level 1

                        thanks for the advice,

                         

                        You could use his matte shape on a horizontal Fractal Noise or treat it with Roughen Edges and Directional Blur.

                        How do i 'use ' or create a matt shape from a layer, i've never acutally explored this area - turning a shape into a mask. Is it somewhere under mode? excuse my ignorance

                        • 9. Re: Keying 16mm, a challenge to the adobe community
                          luadke Level 1

                          You can see how i've been getting along here I still seems very discontected to me. Thank you Rick Gerard your advice on the parallax seems to be helping, i also removed a lot of the blur that was on the train. I really want to try and do some sort of shadow or reflection of the boy on the train to see how that would affect all this. Obviously the train is changing shape all the time so the shadow/reflection should change accordingly, I've just been messing around with drop shadow which is really the wrong way to go. Still not shure how to make a matt into a shape. I gues i could try just distorting a mask. Please give more suggestion if you can, thanks

                          • 10. Re: Keying 16mm, a challenge to the adobe community
                            Mylenium Most Valuable Participant

                            I meant simply to duplicate the keyed layer a bunch of times and treat it creatively. Pre-compose the result and with the alpha info then baked in, it is possible to use most other effects on it without roining the transparency. Then it merely becomes a mtter of the stacking order to see what looks better behind or on top... Sorry for the confusion.

                             

                            Mylenium

                            • 11. Re: Keying 16mm, a challenge to the adobe community
                              luadke Level 1
                              You could use his matte shape on a horizontal Fractal Noise or treat it with Roughen Edges and Directional Blur. Give it a slight dark brownish tint, use Multiply or Overlay and again play with the opacity

                              Hey Mylenium, I've been trying to do what you said by duplicating, but I not really sure how to make these effects create the right shadow. Its just that the train would change his shadow constantly. I have been messing around with them quite a lot but the render times are so slow that it is hard to make good jugments. I made the BG brighter and increased the light wrap width on the boy. You can see that here . And you can see a short shadow test I did here ,

                               

                              Any more advice?

                              • 12. Re: Keying 16mm, a challenge to the adobe community
                                Rick Gerard Adobe Community Professional & MVP

                                The biggest giveaway that I see is that the train is basically the same size in the frame throughout the entire pullout. This makes the boy much too small at the end of the shot and much too big at the beginning. IOW, the perspective is just wrong.

                                 

                                I also think that there's way too much light coming from behind. I much preferred the color grading you did in the first example. It actually looked like there was some reflected light falling on the subject's face as the brighter parts of the train passed by. With all that bright light coming from the train there wouldn't be any shadow on the train.

                                 

                                Hope this helps. I know how crazy shots like this can make you. You might want to take a camera out and shoot someone standing in front of a train and then do a pull out to give you some frame of reference. Come to think about it, you don't even need a train. Any background with a pattern would do. Windows, bricks, anything. This would help you match the background with the foreground so you'd buy the shot.