Blue-Red Gradient on Widescreen Projection HDTV set?

Discussion in 'Archived Threads 2001-2004' started by Tom_Maher, Jul 6, 2002.

  1. Tom_Maher

    Tom_Maher Stunt Coordinator

    Jul 2, 2002
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    I have Toshiba 56X81 and it has annoying 'blue-red' gradient across the screen, starting from the left side and going to the right. Basically, the left side is more blue whereas the red side is more red. Its barely noticeable, if at all, during busy scenes but when there are lots of whites or light colors on the screen, it is notuiceably annoying, enough to pull you out of the film. The movie Vertical Limit shows the off the best, with the snow on the left side of the screen having a noticeable blue tint and the snow on the right side of the screen having a noticeable red tint. I understand that this is due to the nature of projection based tvs, with the blue gun on the left and the red gun on the right, but is it usually this pronounced? Additionally, is there any way I can eliminate or at least minimize this problem? I have done a full calibration with both the Avia and Video Essentials disc and also have done a service mode convergence. Is there anything else I can try? Thanks for the help!
  2. Steve Schaffer

    Steve Schaffer Producer

    Apr 15, 1999
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    Use the "warm" color temp setting if you're not already. A careful manual convergence might also help.

    Professional ISF calibrators deal with this problem using a technique called lens striping, which involves masking parts of the red and blue crts. I don't think this is something the average owner would want to attempt.
  3. Michael TLV

    Michael TLV THX Video Instructor/Calibrator

    Mar 16, 2000
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    Calgary, Alberta
    Real Name:
    Michael Chen

    Go to the keohi site and read up on science and theory of lens striping. Then if you feel up to it, you can do the eyeball version yourself.


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