1080i or 720P?

Discussion in 'Archived Threads 2001-2004' started by Chris Kane, Dec 16, 2002.

  1. Chris Kane

    Chris Kane Extra

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    Just got through editing this post after reading a white paper on 1080i vs. 720p so ignore the title of this post.
    Am I correct in assuming that the first unit would not allow me to take advantage of a progressive scan DVD player?
    Is the input info on the second set a typo (i.e. is it also converting to 1080i?)or does it really display 720p?
    34" FD Trinitron WEGA
    KV-34XBR800
    $2,499.99
    NEW 720p Input Capability (converted to 1080i), Component Video Inputs (2) HD Capable
    34" FD Triniton WEGA
    KD-34XBR2
    $3,999.99
    Video Input 2 HD Capable (1080i,720p,480p,480i) Inputs
    Chris
     
  2. Stephen Tu

    Stephen Tu Screenwriter

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    It's hard to say whether one is "better". They have different strengths. 1080i has higher spatial resolution than 720p, particularly when looking at stationary or slow moving images. But this comes at the expense of interlacing artifacts on fast moving scenes, twittering of thin near-horizontal lines, and reduced apparent vertical resolution in moving scenes, among other things. It's further complicated by the fact that most current sets can't display anywhere near the full resolution of 1920x1080i, nor do the broadcasts themselves contain that much resolution.

    But in almost all cases, the whole point is moot, because the display device only supports one or the other, and the non-native format has to be converted, either in the set or in the HDTV tuner STB. Generally CRT sets only natively support 1080i (& 480p or 540p SDTV), but not 720p. Available fixed pixel technologies (DLP, LCD, plasma) only do 720p (or 768p). Everything else requires conversion. Some sets do this themselves (like the sets you mention, apparently); others require the STB to do it.
     
  3. Stephen Tu

    Stephen Tu Screenwriter

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    In response to your edited questions:

    (1) (prog scan DVD player), no you are incorrect.

    (2) I wouldn't call it a typo, just maybe somewhat less clear statement. It converts 720p to 1080i for display.

    The main difference between the sets is the more expensive one includes a built-in OTA HDTV tuner. (Massively overpriced given the price differential, IMO).
     
  4. Chris Kane

    Chris Kane Extra

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    Stephen,

    Glad to hear that I'm wrong re: #1. But why would a progressive scan DVD player be better than a non-progressive scan unit if the display is only going to convert it to interlaced anyway?

    Lastly, I'd like to get your (and anyone else's) personal opinion.

    Let's say that both units were identical in every way except native resolution. Would you pick 720p or 1080i?

    I would imagine that this would have something to do with the type of movies that one watched (i.e. action vs. non-action).


    Chris
     
  5. Stephen Tu

    Stephen Tu Screenwriter

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    But why would a progressive scan DVD player be better than a non-progressive scan unit if the display is only going to convert it to interlaced anyway?

    It's not going to. 720p is converted to 1080i. 480p DVD is displayed as 480p.

    The real question is why prog-scan DVD when the set itself has a decent deinterlacer and would convert 480i to 480p anyway. Here, in fact the advantage can be rather tiny, especially on this smaller set, maybe not worth it if you already have an interlaced player you are otherwise happy with. The prog-scan DVD tends to be a bit sharper (avoid some D->A->D conversions), and if a good one may avoid occasional line doubling artifacts on a badly encoded DVD.

    Let's say that both units were identical in every way except native resolution. Would you pick 720p or 1080i?

    I don't think this hypothetical has any real world meaning, since CRTs aren't available in 720p.
     
  6. Luke_Y

    Luke_Y Second Unit

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  7. Lew Crippen

    Lew Crippen Executive Producer

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    You might want to confirm the specs for the KV34XBR800 again Chris. I thought that it would display 480i, 480p, 720p and 1080i natively.

    Getting a 720p signal, is another matter, however. Almost all of the older HD STBs (e.g. Hughes E86) only output 1080i (both 480p (Fox0 and 720p (ABC) are converted to 1080i.. Of course the newer STBs output the input without any conversion.

    A progressive scan DVD player supplies 480p directly, so there is no external conversion.

    How much magic the sets internal line-doubler does for display purposes (for both 480p & 720p) is not known to me.
     
  8. Matt_Bradley

    Matt_Bradley Extra

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    I think some of the higher-end CRT TV/Monitors out there will display a 720p signal w/o converting it to 1080i. Princeton Graphics, Monivision, and Sampo come to mind.
     
  9. Chris Kane

    Chris Kane Extra

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  10. Chris Kane

    Chris Kane Extra

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    According to Princeton Graphics:
    Princeton Graphics
    Arcadia 3.4FTW
    Maximum Resolution - 1024x768 (Non-interlaced)
    Does this mean that it will display 720p?
    Chris
     
  11. Chris Kane

    Chris Kane Extra

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    Do you think that they'll give me a discount if I claim that Joe Kane is my uncle? [​IMG]
     

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