"Halo" of light at top of screen on Hitachi 57" RPTV

Discussion in 'Displays' started by JamesOr, Dec 12, 2003.

  1. JamesOr

    JamesOr Agent

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    I have a Hitachi 57twx20b RPTV and there is an obvious "halo" of light at the top of the screen that shows up whenever the screen goes to black or there are black bars for a 2.35:1 movie. There is nothing at the bottom of the screen like this. It's not really visible when there is a full image displayed on the screen, unless it is a dark scene.

    I got this tv on July 1 of this year and pretty much from the early stages I can remember seeing this problem, although I don't remember exactly when I noticed it. I'm mostly worried that it will get worse or more pronounced.

    One thing I've thought of is I have my ReplayTv and my dvd player on top of the tv to either side. I used to have the Directv reciever in the middle but moved that on top of the Replay. Can electronic devices cause problems with a RPTV screen if they are on top of the tv? I did a lot of reading on this board before buying this tv and never heard anything like that.

    I hope I'm describing this problem well enough. The light is irregular along the top of the screen. It's like rectangular blocks of light "bleeding" down the top of the screen, about 2 inches down. If I get real close to the screen while it's paused on a black screen, I can really see the light.

    I'd really appreciate some help figuring this out. I haven't had it professionally calibrated yet. I used the AVIA disc 2 months ago and dialed all the settings in pretty conservatively and always had the brightness/contrast set 30-35 or below prior to that. I have been way conservative with this tv as far as settings and video game playing so I don't know what it could be. Calibrations are included with my warrantee so maybe a tech could diagnose this too. Thanks
     
  2. John S

    John S Producer

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    No speakers that maybe are not so sheilded to close to the set or anything???
     
  3. ChrisWiggles

    ChrisWiggles Producer

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    It's probably lens flare, or light bouncing around inside the screen. Hunt around Keohi, they had some articles about controlling lens flare with striping, and also lining the interior with duvatyne. This may help. Painting the lens assembly inside is something I probably wouldn't risk, but that is mentioned as well.

    Now, in describing your problem, does this occur when the ENTIRE screen is black? Because then this may not be the case. If you're getting light on black PORTIONS of the screen when there are other bright things on the screen (look at credits for instance), then it's probably lens flare/light spill, etc.

    This would not be caused by magnetic interference at all.

    If it's at the edges, it might be image noise, you might need a little more overscan. This would look not like halos or light spill, but very clear noisy stuff right at the edges of the picture.
     
  4. JamesOr

    JamesOr Agent

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    Thanks for the replies. The light is there all the time, though obviously it's most visible when the entire screen is black- like during a transition or something. It's definitely not caused by other light on the screen, like credits or text. I can see it even when there is a full image on the screen, though it is harder to see since there is video playing.

    It isn't any kind of noise or distortion, just plain light. It's obvious enough that it draws your eyes to it when you are watching a 2.35:1 movie or there is a transition where the screen goes to complete black.

    I don't have any external speakers hooked up to the tv, I use the speakers in the tv itself for everything so it's not a shielding problem.

    It's sounding more and more like something I will have to have a tech look at. I wanted to make sure that it wasn't the components I put on top of the tv before calling them. Looks like there is something that needs to be adjusted or fixed. Any other suggestions would be helpful but it looks like I'll be calling a tech on Monday.

    What is the general rule for getting the first pro calibration? This thing is going on 5 months old, is that a good time to get the first calibration anyway? It's been a while since I did the research on RPTV's and I've forgotten a lot of the stuff I learned
     
  5. Jim0de

    Jim0de Auditioning

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    I have a 57S715 and I notice a small halo about 3/4 of the way up from the bottom of the screen even when the set is off. I checked to make sure it wasn't just a reflection from something in the room and it's not. It's definitely coming from inside the set, so I'm assuming that it is due to some sort of light being reflected within the set. It's not so bad that it's distracting, but if you know it's there and look for it you can see it at times depending on what's on the screen at any given moment.
     
  6. henning hoffmann

    henning hoffmann Stunt Coordinator

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    Internal reflections like this are quite annoying. I never knew this was a problem until I bought my Hitachi 57T500 last year. There is a small light near the center of the screen even when the TV is off, but this is normal for RPTVs. Plus, when there are bright parts of an image, I get washes of light elsewhere. Very annoying.

    henning
    www.hdblog.net
     

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