Does a 768p plasma look best with 720p or 1080i?

Discussion in 'Displays' started by Joe Pick, Oct 28, 2007.

  1. Joe Pick

    Joe Pick Stunt Coordinator

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    What's the most optimal video resolution setting for a Panasonic TH-50PX75U? It's native resolution is 1366x768 and it always says (720p in parenthesis). I have a Motorola cable box and an Oppo 981 DVD player, and I can choose 1080i or 720p with both. The TV is 50" and I sit about 9.5 feet away. I've tried both, and I'm not sure I can see a difference.
     
  2. Joe Pick

    Joe Pick Stunt Coordinator

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    Anyone? By the way, the cable company and Oppo have not really answered the question. What setting would you choose, and why?
     
  3. Patrick Sun

    Patrick Sun Moderator
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    The Panasonic does a good job with de-interlacing the 1080i video source information, which is why you don't much difference between 1080i and 720p sources. So, you just have to trust your eyes and pick one. If it keeps you up at night that the plasma does de-interlacing of 1080i, then pick the 720p option.

    (Disclaimer: I own last year's Panasonic TH-50PX600U model)
     
  4. Kevin C Brown

    Kevin C Brown Producer

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    I wouldn't discount sending the plasma 480i or 480p too, for DVD or SD video.

    The reason why is that if you send 720p, the plasma still has to upscale to 768p, so that's 2 upscaling operations, one by the player (or cable/satellite box), and one by the display. You might get a better picture if you just let the display do everything ... once.
     
  5. Allan Jayne

    Allan Jayne Cinematographer

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    Regular DVD, I suggest outputting 480i or 480p and see what looks better.

    Hi-def DVD, You'll just have to see what looks better.

    Cable box, I suggest native, namely 480i for the 480i shows, 720p for the 720p shows, etc.

    For 720p shows or 720p input, try decreasing the picture height (vertical size) to see if a sharp sweet spot develops (with 720 rows of pixels in use). If the same scaling process that does the final conversion to 768p also controls the VSIZE, you might luck out.

    There is no choice about converting 1080i in order to get it on your screen. Very few TV's do 1080i to anything else well, but very few cable boxes even match that. Very few cable boxes do 480i to anything else well. DVD players and TV's on average do 480i to 480p about the same but individually it varies all over the map.

    DVD player outputting 480i: Player does nothing. TV does 480i to 480p then 480p to 768p.
    DVD player outputting 480p: Player does 480i to 480p and TV does 480p to 768p. No unusual problems.
    DVD player outputting 720p: Player does 480i to 480p and 480p to 720p, TV does 720p to 768p. Here is where extra processing can half kill you.

    Hi-def DVD outputting 720p: Player does 1080i to 1080p and then 1080p to 720p (Or 1080i directly to 720p). TV does 720p to 768p.
    Hi-def DVD outputting 1080i: Player does nothing, TV does 1080i to 1080p and then 1080p to 720p. (Or 1080i directly to 720p)
    The parenthesized processings are usually inferior. For film source disks, the player will probably do 1080i to 1080p better than the TV and might do 1080i to 720p better than the TV can do 1080i to anything.

    Video hints: http://members.aol.com/ajaynejr/viddoubl.htm
     
  6. Steve_L_B

    Steve_L_B Stunt Coordinator

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    We have a 50" Panasonic 768p plasma, and for most HD content, I can't really see much difference in PQ between outputting 720p and 1080i from our Comcast HD cable box. One exception is sports programming that originates in 720p (ABC, ESPN, FOX), where 720p output definitely looks better. In particular, fast motion and camera pans look smoother, epescially for football and hockey.

    -Steve
     
  7. Mark Murphy

    Mark Murphy Supporting Actor

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    I have a 768p Sony Bravia and for whatever reason, 1080i looks much better than 720p. That goes for both my HR20 and my Oppo 971H. I'm using HDMI for both but noticed it as well with the HR20 using components.

    With 720p, the picture seems to be a whole lot grainier on both sources while 1080i seems smoother but not soft. I can't explain it but it what it is.
     
  8. Joe Pick

    Joe Pick Stunt Coordinator

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    Where can you find out which networks broadcast at what resolution?
     
  9. Jeff Gatie

    Jeff Gatie Lead Actor

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