Question about "ghosting effects"

Discussion in 'Displays' started by Joe Karlosi, Jun 25, 2004.

  1. Joe Karlosi

    Joe Karlosi Producer

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    I hope I'm in the correct forum for this question, but I'm also hoping someone can give me some advice...

    I have a SONY 36" television, about three years old. Whenever I'm watching a DVD (and it can also occur with regular broadcasts), I have what I can only call a "ghosting problem". Let me elaborate as best I can ...

    I'm not referring to "people" having a ghostly "double outline" image. Let's say there is a dark night scene, and someone is carrying a candle on the left side of the screen. It's almost as if the light off the flame creates a horizontal line of light across the entire length of the screen, to the right. This can also occur with credits (usually bright white lettering against a solid black background throwing off "light" across the screen). Other bright images may "throw off" a horizontal line to the right like this, too. Recently I've seen it occur off a person's hair!

    I've tried adjusting brightness and contrast in all sorts of ways, to no avail. Any advice would be appreciated.
     
  2. Jack Briggs

    Jack Briggs Executive Producer

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    Hi there, Joe.

    You're witnessing what is known as "phosphor lag." Nature of the beast here. The refresh rate is not fast enough to recover from the bright-object/dark-background scene in order for you not to notice it.

    A way to minimize this is to have your user-menu picture controls adjusted properly. And since you've been here for quite a few months, I'm sure you know the drill on this.
     
  3. Johnny_M

    Johnny_M Second Unit

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    I have the same problem, I adjusted my brightness and contrast using a DVE dvd, no help. It was like this when I bought it so I learned to live with it.

    Is your tv an RPTV Joe? Thats what I have. Is there no way to adjust this? I have access to my service menu, but I dont want to adjust anything without knowing.


    Johnny
     
  4. Jeff W.

    Jeff W. Stunt Coordinator

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    I have this on my 27" Sony WEGA tube. I first noticed it on Star Trek DVDs I think, all the stars in the opening have a line coming off them pointing to the right. Turning the contrast down helps a lot, but there will still be some feignt lines visible if you go up and look real close, but generally not distracting during normal viewing.

    [​IMG]
     
  5. ChrisWiggles

    ChrisWiggles Producer

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    The way you described this, I'm going to disagree with Jack. This is not phosphor lag, as phosphor lag only is short-lived and affects only what was *previously* brightly lit. What you are seeing is horizontal streaking across the entire screen to the right, I assume, that remains even if you pause the picture, and usually from bright parts of the picture. For instance bright stars or something would streak to the right.

    This is an electronics problem somewhere, it may or may not be easily fixable(it may be poor design), but you can have it looked into. It is likely not something that can be calibrated away, though service adjustments may come into play if something is bonkers in the guts of your set. Either way you should get it looked at.
     
  6. ChrisWiggles

    ChrisWiggles Producer

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    This is probably something like the streaking you are describing, is it not?:

    http://archive.avsforum.com/avs-vb/a...874&fullpage=1

    If so, not phosphor lag, and something somewhere is a little wrong. I would try to rule out cabling, bad power, etc first. Otherwise... service...
     
  7. Joe Karlosi

    Joe Karlosi Producer

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    Yes this remains even when I pause the picture. I've done this to try and work on it as I adjust the controls. There doesn't seem to be much I can do about it, though reducing contrast helps a bit.

    I should also mention that this can be less severe depending on which DVD I'm watching.

    By the way everyone -- thanks for all your feedback.
     
  8. Joe Karlosi

    Joe Karlosi Producer

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    Yes, that's it. Although on the screenshot it's not as noticeable.
     
  9. ChrisWiggles

    ChrisWiggles Producer

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    Ok, well it could be a cable problem (most likely) I'd try swapping cables, etc, trying different inputs, try to see where the problem is first. It may also be a problem in the set which you should get fixed if it's not a cabling problem, etc.

    It may not be "broken" per se, but there are service adjustments that may be off that may cause this problem.
     
  10. Joe Karlosi

    Joe Karlosi Producer

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    I already have a Sony DVD Player [​IMG]
     

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