letterbox mode vs. compression mode: spot the difference?

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

  1. EricW

    EricW Cinematographer

    Joined:
    Jan 1, 2001
    Messages:
    2,308
    Likes Received:
    0
    Trophy Points:
    0
    hi

    i have a 36" 4:3 HDTV tube and whenever i test a picture in letterbox mode (grey bars), i can't see the picture difference as opposed to full resolution compression mode. could someone give me a scene from a DVD and tell me what part of the screen to specifically look at to see the difference?

    for reference, i have a tosh 36hfx72, pioneer 333 player, and component video cables from MIT

    thanks
     
  2. JasonRH

    JasonRH Second Unit

    Joined:
    Jan 8, 2001
    Messages:
    496
    Likes Received:
    0
    Trophy Points:
    0
    Eric,
    There is a difference since you are getting more resolution for the compressed picture, though I don't know how to describe the difference you'd see. Think of changing resolution on a computer monitor - the picture just looks more refined with better detail.

    I was actually considering purchasing the set you have, but wasn't sure that it even did the squeeze on DVD input. The website description is a bit confusing and suggests that it might be only for 1080i sources. Glad to see that isn't the case. When you use vertical compression does it still show grey bars or black?
     
  3. EricW

    EricW Cinematographer

    Joined:
    Jan 1, 2001
    Messages:
    2,308
    Likes Received:
    0
    Trophy Points:
    0
    i'm sure there is a difference, but i have a hard time spotting it [​IMG] i've done freeze frames and compared, and it's difficult.
    in letterbox (less resolution) mode, the bars are grey (the thinking is if the tv scans onto the whole screen, there will be less burn-in) and in compression/full resolution mode, the bars are black.
     
  4. Jason Merrick

    Jason Merrick Supporting Actor

    Joined:
    Mar 2, 2000
    Messages:
    696
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Simi Valley, CA (Los Angeles)
    Real Name:
    Jason Merrick
    Eric,
    On my 27" JVC it took me a while to recognize the difference. Now I can easily see the improvement. From a fairly close distance, look at the scanlines that run from side to side while watching an anamorphic DVD in regular non-anamorphic mode. Then watch the same DVD in anamorphic and you will barely even be able to see the scanlines.
    Huge difference in my opinion. Even my wife can see it! (And isn't that the true test? [​IMG] )
     
  5. John-Miles

    John-Miles Screenwriter

    Joined:
    Nov 29, 2001
    Messages:
    1,216
    Likes Received:
    3
    Trophy Points:
    110
    The toshiba is an awesome tv. but i must say ive never noticed any specific difference either, its just a general improvement. and yes it does the squeeze on everything 480i/p and 1080i
     
  6. ManW_TheUncool

    ManW_TheUncool Producer

    Joined:
    Aug 18, 2001
    Messages:
    6,015
    Likes Received:
    40
    Trophy Points:
    6,610
    Location:
    The BK
    Real Name:
    ManW
    FWIW, I've only done comparisons a long time ago between my PC w/ Realmagic Hollywood Plus playback and my old 32" Toshiba w/ a Toshiba player, and I was able to confirm 16x9 downconversion artifacts I had been seeing in some scenes.

    Usually, the most visible cases are the ones that involve thin horizontal patterns w/ slow vertical panning or mild bobbing of the camera. A good scene for this is the staircase scene near the beginning of Ronin. On my old TV+DVD setup, the steps are clearly flipping between light and dark as the camera pans down to following DeNiro down the steps.

    Sometimes, scenes w/ sharp small details will also show artifacting during vertical panning. One scene that I noticed was the beginning of A League of Their Own just before you see Geena Davis pack for the league reunion. I can easily see details shifting/crawing and disappearing/reappearing as the camera pans up and around the room before settling on Geena Davis. Another really good scene for this is in Dark City when the camera zooms out to show the city after they discover the truth about it.

    Other frequently viewed scenes w/ similar effect are nighttime, star-filled sky scenes (or deep space in sci-fi's also). The opening scene of Toy Story 2's a good one. You'll see stars disappearing/reappearing as the camera pans--might need to run it in slo-mo to be obvious.

    In all cases where I've seen artifacts, I was not actually looking for them. And actually, doing freeze frames is not an easy way to locate them. If you want to look for them, use slow scanning playback.

    Yes, interlaced video will also exhibit some similar artifacts and/or "enhance" them. So in your case w/ a progressive player, they may be less noticeable because of that.

    Finally, different players--mostly different brands--will do the 16x9 downconversion differently to show different types of artifacts. In my case w/ the Toshiba player, I get those artifacts. For some other players like Sony, you'll get a noticeably softer picture to overcome those artifacts. But it comes at the cost of a softer picture. Other brands/players, including the Pioneer's, do something in between, so that's one more plus for you. But I'd imagine that you should notice a sharper image w/out the downconversion.

    And as always, YMMV.

    BTW, IIRC, your Pioneer 333 does not actually do 3:2 pulldown, so if you want a sharper/better picture, you should consider getting a new player. In fact, you might want to check to see if you won't get a sharper/better picture using the TV's linedoubler(!), instead of the Pioneer's.

    _Man_
     
  7. JasonRH

    JasonRH Second Unit

    Joined:
    Jan 8, 2001
    Messages:
    496
    Likes Received:
    0
    Trophy Points:
    0
    John,
    I noticed you have the HFX71. I wonder if this years model was changed (HFX72), similar to the new Panasonic Tau series direct views only squeezing 1080i sources?
     
  8. John-Miles

    John-Miles Screenwriter

    Joined:
    Nov 29, 2001
    Messages:
    1,216
    Likes Received:
    3
    Trophy Points:
    110
    Hmmmm I'm not too sure to be honest, I know mine does the squeeze on everything 480I/P and im pretty damn sure it does it for 1080i as well, but i dont ahve HD to test this.

    I cant see them removing this feature from the new models though.
     
  9. Patrick Sun

    Patrick Sun Studio Mogul

    Joined:
    Jun 30, 1999
    Messages:
    38,761
    Likes Received:
    485
    Trophy Points:
    9,110
    Crowd scenes at a sporting event on DVD will look better in its native 16x9 mode, than its downconverted mode.
     
  10. JasonRH

    JasonRH Second Unit

    Joined:
    Jan 8, 2001
    Messages:
    496
    Likes Received:
    0
    Trophy Points:
    0
    John,
    I wouldn't think that Toshiba would take away that feature either but I didn't think Panasonic would and they did. It's likely there but I just found the web site description a little vague and the change in Panasonic Tau's had me concerned.
     
  11. Patrick Sun

    Patrick Sun Studio Mogul

    Joined:
    Jun 30, 1999
    Messages:
    38,761
    Likes Received:
    485
    Trophy Points:
    9,110
    Also, watch the text scrawl up in either The Phantom Menace or The Attack of the Clones on DVD at the beginning of the movies. It's pretty evident what happens when you use downconverting of 16x9 encoded DVDs vs. watching 16x9 with the correct vertical compression of that video signal. The small letters get wonky as they scrawl upwards in the downconverted video signal.
     

Share This Page