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hitachi 42pd5200/panasonic 42pv500/pioneer 42xde problem

Discussion in 'Plasma TVs' started by usman24, Jun 21, 2005.

  1. usman24

    usman24
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    I just got my Hitachi 42pd5200 picked up for repair via hitachi-strange pink patches on white and grey sufaces and feint white vertical stripe on dark scenes. Meanwhile I am looking for a new 42" plasma. My main concerns are black level and hd resolution. I have always wandered why via my denon 2910 watching a pal dvd [ntsc works fine]it was not displaying 720p correctly [hdmi-dvi] and would only display 1080i [inferior quality?] I have now discovered that it will not support 720p when sky broadcast hd @720p [new model hit7200 does].

    Can anyone recommend a solution and or an alternative plasma such as pansonic 42pv500 or pioneer 42xde for black level quality, 720p [pal] resolution compatibility? Which one would be better?
     
  2. Cable Monkey

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    There is a version of the 42pd5200 suffixed H that is supposed to be able to accept 720p 50hz. I wonder if there would be a possibility of an upgrade for those of us with original 5200Es. A possible business opportunity for someone in the industry?
     
  3. maltese

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    Your Hitachi 42pd5200 should support 720p (unless there were a problem with previous units), but as far as I know it will have to downscale the 720 lines to 512 lines in order to display as a progressive scan signal.

    Regardless 1080i, that kind of signal is in fact superior quality in terms of resolution (1080 lines versus 720 lines) but as an interlaced signal you will probabily notice little flickering that you won't notice in a 720p signal as it is pure progressive scan. All 1024x1024 screens are best alternative nowadays for 1080i.

    Similar problem will happen to panasonic or any other 1024x768 screen in order to display a 1080i signal. I don't know the process in detail, but sure you will lose quality.

    So if you want your plasma display to watch 720p you'd better choose a 1024x768 screen, but it is important to be aware of 1080i future problems.

    -m
     
  4. Cable Monkey

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    The problem is the screens ability to dispaly 720p @ 50hz. The peculiarities of an Alis screen is it rescales all resolutions. Even its own native resolution. There is no way around that process. However what usman24 and others like me would like is a means of getting it to accept Skys proposed transmissions. Has the 720p 50hz standard been accepted as the way to go in Europe?
     
  5. Nick_UK

    Nick_UK
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    Are you sure you know how an Alis panel works ? It doesn't look as if you do :thumbsdow
     
  6. maltese

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    sorry if I made some mistakes, maybe you could show us the light with all your wisdom, master.

    I read what I wrote in other forum's FAQ:

    http://www.avsforumfaq.com/~plasma/#alis

    Check it out and, please, I would be very grateful if you could teach us something.

    -m
     
  7. Cable Monkey

    Cable Monkey
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    Many peoples interpretation of ALIS is that it scales everything up or down to 512 lines, then doubles it to 1024 lines using a 'simultaneous interlace' method (both fields are flashed up at the same time) that reduces flicker. The theory that it takes 1080i and simply chops a bit off the top and bottom is as far as I can tell just that. A theory. Much of how ALIS performs is also down to how the maker of the package applies it so it is not a simple 'one explanation suits all'.
     
  8. maltese

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    Ok, maybe you are right, but as far as I know by reading official Hitachi documents, the Hitachi ALiS panel is divided in two 1024x512 fields and can display different fields in each one.

    http://www.hitachidigitalmedia.com/DMG/tech_plasmon.jsp

    Furthermore, never heard about the "simultaneous interlace" method and I would say that's wrong as it is opposed to the concept of "alternative lighting surfaces" that ALiS stands for.

    In fact, I think that it is the own nature of the ALiS panel, so it would apply to every manufacturer using that panel (all of them are made by Fujitsu-Hitachi-Sony consortium).

    The way an ALiS plasma downscale or upscale a particular signal could be up to the manufacturer, but I bet all of them would try to give the best picture quality and no way they could "simultaneous interlace"

    What makes ALiS special is that because of the fact that it has smaller pixels it has much more "image surface" than a convencional 480 lines plasma and this can make, for example with a 576p signal which is downscaled and doubled, the image brighter and much more cinematic as you cannot notice the pixel structure, and this way you get progressive display and no flickering.

    With a 1080i signal the main goal would be to get the best picture quality. This signal is in fact divided in two fields of 540 lines each one and uses same interlaced method ALiS can display. It would be a waste of capability (and even more, a much more difficult goal) to downscale instead of just cropping few top and bottom lines.

    -m
     

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