LCD picture quality

Discussion in 'Displays' started by Samuel_Fred, Feb 6, 2004.

  1. Samuel_Fred

    Samuel_Fred Stunt Coordinator

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    So I just got a Sharp 30" LCD and am surprised that the picture quality isn't quite as sharp (pun not really intended) as I expected. Most peculiarly, there's a good amount of blurry-ness and even small amounts of pixellation. This is especially noticeable when you look close up at the TV. From further away (where one would watch it from anyway) it looks much better. Is this normal? I also notice that straight lines are sometimes jagged (especially close up) and that a series of horizontal lines in the image (like someone's striped shirt) can flicker. I've tried looking at DVDs in 1080i and 720p (with DVI) and at 480p (with component) and I really don't see much of a difference. I am unable to properly view 4x3 films with the DVI hook-up, but these actually look better than any widescreen images (strangely). Any thoughts?
     
  2. David Parrish

    David Parrish Stunt Coordinator

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    You've got a lot of complicated questions in your post, and I can't answer all of them. I'll try to help, though.

    1080i and 720p are scaled to fit your screen by the TV's innards. Once you reach your LCD's resolution limit a higher res signal will yield no extra detail.

    Pixelization is a fact of life with an LCD tv. Don't watch it so closely!

    If you have blurry images or shadows, you may not have your TV properly calibrated. Go into your DVD collection and find a THX certified DVD with the video calibrator( Star Wars II comes to mind). This may help.

    Good luck!
     
  3. Leo Kerr

    Leo Kerr Screenwriter

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    We've had a variety of 16-20" LCD panels at work for NTSC displays.. some Sharp, some Boland, and some NEC.

    On VGA signals, they typically look pretty good.

    On NTSC signals, they seem to have non-defeatable sharpness amplifiers, in addition to a low-pass filter that blurs everything - giving everything a sort of fuzzy outline. It's really strange.

    However, the DVI signal should bypass the analog filtering circuits.

    In short, "strange."

    Leo Kerr
    [email protected]
     
  4. Samuel_Fred

    Samuel_Fred Stunt Coordinator

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    Pixelization is a fact of life with an LCD tv. Don't watch it so closely!


    But I thought LCDs were supposed to have some of the best resolution. What am I missing here?

    Also, although the correct geomatry on 1.85 and 2.35 films is great (nothing cropped), the TV doesn't know what to do with 1.66 or 1.78 ratio films and just displays them as 1.85, which means I'm losing image (a real shame). Also, the "side bar" mode for 4x3 images not only locks in at 1.33 (which is bad for 1.37 films), but it crops about a total of 12% from the sides. Why?
     
  5. David Parrish

    David Parrish Stunt Coordinator

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    I was only trying to say that from too close a distance any TV looks bad. The image doesn't looks its best unless you sit in the manufaturer's recommended viewing area.

    Now if its blurry and pixellated from your couch 8 feet away, I'd have it checked out. The high quality flat LCDs I've seen look like a window( very realistic) from standard viewing distances.
     
  6. Samuel_Fred

    Samuel_Fred Stunt Coordinator

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    Thanks David.
    Well just for kicks I plugged my computer into the LCD and played some DVDs from WinDVD. This solved all problems of correct display ratio, since the computer automatically resizes the picture to its correct dimensions. I was surprised how good it looked. The pixellation problem I was having seems to have disappeared! Color isn't exactly as good, but I could adjust the set some more. Should this be the case: that I get better (or at least just as good) image quality from a PC hooked up to the PC input as a DVD player outputting 1080i with DVI? Anyone? Now if I could only get my sound to feed properly through my stereo -- this, I imagine, is not likely.
     
  7. Samuel_Fred

    Samuel_Fred Stunt Coordinator

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    To follow up on my own post: what's the difference (technically) between what my computer is outputting and how the TV displays it and what my DVD player is outputting (through DVI at 1080i or 720p) and how the TV displays that?

    I'm really starting to think seriously about just watching films from my computer ...
     
  8. Leo Kerr

    Leo Kerr Screenwriter

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    Caveot: I know nothing useful about the DVI port.

    That said, traditionally, HD modes such as 1080i and 720p are delivered through Y-U-V component video color encoding.

    PCs traditionally deliver R-G-B color.

    While it can be screwed up, I find that highly unlikely.

    Next point: your PC may have a lot more and/or better tricks, power, et cetera, to throw at video processing than the DVD player or screen. Also, when the PC is set right, the PC can be bypassing almost all of the circuitry in the LCD display, essentially telling each pixel what levels of the RGB triad it should be displaying.

    Reflections on what little I know of DVI:

    my recollection is that in the many pins in a DVI connector, there is (potentially) analog and digital signaling. If this is the case, then it is possible that your DVD player is only feeding the analog side, while your PC may be feeding both. This, I warn, is speculation, based on the fact that we have a DVI->VGA adapter on our second port on our video board, and it takes no external power. (Of course, DVI could also provide power, too, but I don't know.)

    Leo Kerr
    [email protected]
     
  9. Samuel_Fred

    Samuel_Fred Stunt Coordinator

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    After some testing I can say that the RESOLUTION from the PC is definitely better, whereas the color is not so good. The color from the DVD player (DVI or component) is great, but the resolution is poorer. If only I could get the best of each of these...

    Is it possible to get my PC to output Y U V color like the component cables on a dvd player?
     

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