9 Replies Latest reply on Mar 8, 2013 4:31 PM by Matt Dubuque

    Chroma keying issue

    Yiannis72 Level 1

      Watch this clip to understand my issue...

      http://www.youtube.com/watch?v=05Cu56i9NCw

       

      Thank you.

        • 1. Re: Chroma keying issue
          Rick Gerard Adobe Community Professional & MVP

          I'd suggest using more than one copy of Keylight to create your key. The noise is being caused by some reflections in the hair and the jumping is caused by the zoom. I've done shots that had 4 or five copies of the footage all masked to key separate areas. You just have to tweak the individual sections to fix the problems with the edges. This is a common problem.

           

          Just duplicate your layer and add another mask so you're only tweaking the parts of the key that are causing problems. I think 2 layers would do it.

          • 2. Re: Chroma keying issue
            Yiannis72 Level 1

            In some clips I have done that in order to key separately the head and the rest of the body. I stil got some issues with the hair... less but enough... The light reflection on the semitransparent areas sush as hair is DEATH.... I have to twick for days.... Imagine to do this in 117 clips..... AAA!!!

             

            Thank you for the valueable tip!!

            • 3. Re: Chroma keying issue
              Dave LaRonde Level 6

              I'm sorry, but I did not have more than 9 m,inutes to devote to the entire clip. However, I see two things that can really hurt you: wrinkles on the green screen background and hot spots from the lights on the background.  These are the things that will keep you from the automatic process you seek. 

               

              Unfortunately, there rarely is anything automatic about a chroma key.

              • 4. Re: Chroma keying issue
                Yiannis72 Level 1

                Hotspots and wrinkles have been taken care of since they have been masked out. That's not the problem..

                • 5. Re: Chroma keying issue
                  Rick Gerard Adobe Community Professional & MVP

                  You might want to take a look at this reply and borrow some of the keying techniques.

                  • 6. Re: Chroma keying issue
                    Dave LaRonde Level 6

                    Then let's move on to the nature of the footage: since this is a chroma key, and chroma keys need accurate color information to key accurately, what is the media container and the codec of the footage being keyed?

                     

                    A hint: DSLR's are not good for this kind of work.

                    • 7. Re: Chroma keying issue
                      Yiannis72 Level 1

                      No it's not DSLR. What is done is done. Now it has to be fixed. Even worse green screen plates can be fixed. So I know this can be easily fixed. I have just forgotten how I twicked the previous project and had a perfect outcome. If I had 4:4:4 sampling format and perfectly lit footage, then I wouldn't need any specific green screen plugin.... These two chroma key plugins are very good and they can fix some inperfections of the originaly shot footage... It's 4:2:1 (my camera). 4:2:2 would be ideal and 4:4:4 (no need)...

                      It's a pitty that Dslr has a fantastic picture quality and such a poor compression format...

                      • 8. Re: Chroma keying issue
                        Yiannis72 Level 1

                        Whenever I work with green screen footage, I always use totaly uncompressed clips. I exported the AVCHD full HD files into totaly uncompressed MOV.......... Of course AVCHD is not good in the first place but it is more than usable....

                        • 9. Re: Chroma keying issue
                          Matt Dubuque Level 1

                          When you said that you forgot the settings of your previous tweaks for me that indicates that you would be well served by understanding some of the fundamentals behind the knobs and sliders we use in AE.

                           

                          In terms of compositing, Mark Chrisiansen's approach is first rate.

                           

                          But learning all this so that you can be more and more flexible as each new adventure arrives is going to take you more than 11.4 minutes.

                           

                          I know time is precious, but why not budget 42 minutes over the next three days (use the stopwatch on your cell phone) to ONLY carefully study compositing and really studying what is needed to blend the perspectives and shadows of two different images so that your work will "fool" more people?

                           

                          No interruptions, just 42 minutes of focused attention.

                           

                          That would be well worth it.

                           

                          42 minutes.

                           

                          Good luck.   Fun isn't it?