3 Replies Latest reply on May 24, 2009 10:21 PM by Mylenium

    Getting Rid of Motion Jitter

    joestak Level 1

      I'm working with a comp where I have one image move across others that are all lines up.  The movement is straight from left to right.  However when I watch what I render out, it is sort of jittery.  I can't easily read the words that are moving past.  How can I aleviate this issue?  I'm working in HDV the comp is in 29.97 square pixels.  IS there a way to smooth the motion so it is not hard to read passing words?

       

      I hope to get some good answers

       

      thanks.

        • 1. Re: Getting Rid of Motion Jitter
          Navarro Parker Level 3

          Are you editing 720p or 1080i?  It might be an interlacing issue.  I believe 1080i is always Upper Field First for both 50i and 60i.

          • 2. Re: Getting Rid of Motion Jitter
            Rick Gerard Adobe Community Professional & MVP

            There are certain speeds that just jitter. There's no way around it except to change the speed or add enough blur to hide it. I wrote a fairly complete explanation of the effect recently.

             

            You'll find the thread HERE. I suggest you give it a good going over.

            • 3. Re: Getting Rid of Motion Jitter
              Mylenium Most Valuable Participant

              In addition to Rick's comprehensive explanation of the quantum mechanics involved , also consider a few other things besides adding additional (motion) blur or changing the speed.

               

              - Try to work with slightly curved motions, if that is possible. The per-frame difference of the area covered in pixels will change and may be more suitable to disguising any artifacts. In addition, in general it will look more interesting.

               

              - Consider shifting the colors ever so slightly, especialyl near the edges. Certain combinations of colors are known to cause problems because their contrast range is too far apart, especially once converted to YUV color for TV display. A good and simple way is e.g to work with the Inner Glow layer style, its color set to something similar to the BG (or black) and opacity reduced to 10 to 20%, so the edges are dampened and blend in.

               

              - Similar to the previous, look for colors "that hurt the eyes" even when the images is standing still. Use selective color correction tools to make them stand out a little less.

               

              - If your source are compressed, e.g. JPEGs from a lower end digital camera, reduce the block artifacts. These may cause additional "trails" when animating the images.

               

              Mylenium

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