RPTV Brighter in the center? Normal?

Discussion in 'Displays' started by Johnny_M, Jun 26, 2004.

  1. Johnny_M

    Johnny_M Second Unit

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    Recently I started to notice my TV looks slightly brighter in the middle of the screen. Ive had it for about a year and never noticed it before. Its really only noticable with a black background and text. Is this normal for an RPTV?


    Johnny
     
  2. Steve Schaffer

    Steve Schaffer Producer

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    To a certain extent it is perfectly normal for almost any rptv to be a bit brighter in the center.

    The effect can be minimized by using a lower contrast setting and veiwing in a less brightly lit room.

    If the effect has become more noticeable over time, it may be that the lenses on your crts need cleaning. I had this effect become more obvious, accompanied by what looked like an increase in internal reflection in the set--a bright object in a largely dark scene would cause blacks to look grayer and black lines at top and bottom would seem to take on a tint of color from bright onscreen objects to a greater degree than previously (though this is a normal characteristic anyway). Cleaning the lenses on the crts made the set look better than new.

    Guy Kuo of AVIA fame has posted a good cleaning method here and elswhere, might try a search.
     
  3. ChrisWiggles

    ChrisWiggles Producer

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    Yes it's normal, brightness and color uniformity is relatively poor with CRT-projection displays, and often particularly so with short-throw RPTVs. If it's particularly bad, check the optics and such as mentioned.

    It should be easiest to see with full-white scenes and such usually.
     
  4. Max Leung

    Max Leung Producer

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    Yep, perfectly normal. It doesn't bother me...you won't notice unless you stare at pure white screens all day. [​IMG]
     
  5. Michael TLV

    Michael TLV THX Video Instructor/Calibrator

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    Greetings

    Normal. In fact, even direct view tube sets have light drop off as much as 50% from the center. Visually, it makes little impact to our eyes though.

    Regards
     

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