CRT with curved or flat tube, geometry problems

Discussion in 'General Gaming' started by helakustorm, Jan 21, 2018.

  1. helakustorm

    helakustorm Robust Member

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    Hello,

    I've read some articles about the CRT geometry that said the curved tubes are better than the flat tubes.
    Myself have a flat CRT, Sony Trinitron to be precise and I can confirm that it have some geometry problems, not a big issue but sometimes it disturbs the eye (sadly I'm a perfectionist).
    What do you think or how to do you fix this?

    Thanks!
     
  2. Armorant

    Armorant Spirited Member

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    Buy another curved CRT or Plasma TV. Kuro series or one of the last Panasonic model.
     
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  3. TriMesh

    TriMesh Site Supporter 2013-2017

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    How bad are you talking about? Flat screen TVs had logic in them to apply geometry corrections to the video signal and the Sony stuff was normally pretty good. If it's terrible, it might be worth investigating the service mode on your TV to see if you can improve it. If it's minor, then it's probably as good as it's going to get.
     
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  4. helakustorm

    helakustorm Robust Member

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    Not very bad to tell you the truth TriMesh
    For example some corners are not align like you see the image on a LCD but it's OK.
    My question was if does exist a CRT TV with flat or curved tube that have perfect geometry like an LCD.
    Here I refer to consoles on CRT only.
     
    Last edited: Jan 21, 2018
  5. Kaeser

    Kaeser Rising Member

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    In theory most CRT TVs can achieve 'perfect' geometry, whether they're flat screen or curved. In practice flat screen CRTs can be more prone to geometry issues at the sides. In my opinion, accepting even tiny imperfections in geometry is part and parcel with having a CRT.

    Some TVs are easier to adjust than others - some have service menus and others need manual adjustment. However, I would recommend trying out the 240p Test Suite to get a better picture of exactly what you think needs improving.
     
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  6. helakustorm

    helakustorm Robust Member

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    Kaeser thank you for your recommendation.

    I have test it on my modded PS1 PAL slim (with RGB sync on luma cable from RGC site; it's the shielded cable not the double shielded one) and these are the results:
    - Grid: https://imgur.com/a/Cx780
    - Linearity: https://imgur.com/a/tt8iz
    - Overscan: https://imgur.com/a/fVDGg
    As you can see on the grid and overscan pattern test there are some little problems; hardly noticeable on linearity pattern test.
     
  7. Kaeser

    Kaeser Rising Member

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    At a first glance I'd be pleased with those results. Give the scroll test a go as sometimes you might see the sides warp a bit.
     
  8. davedoc84

    davedoc84 Newly Registered

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    Sorry to dig up an old thread. If my CRT is warping towards the edge of the picture, what settings could I adjust to straighten this out? More than happy to post the 240p test suite pattern from my Trintron CRT with the Service Menu values on it.
     
  9. Kaeser

    Kaeser Rising Member

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    Take a photo of the grid pattern for starters. Here are some examples of what might be going on [​IMG]
     
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  10. davedoc84

    davedoc84 Newly Registered

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    I will do exactly that and take a photo of the Grid from the 240P test suite.
     

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