LCD tv's

Discussion in 'Displays' started by Jon Cheung, Oct 24, 2004.

  1. Jon Cheung

    Jon Cheung Stunt Coordinator

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    hey guys, i've been lookin around the net and on forums to find out some good infomation on these tv's but I couldn't find anything. Can you guys fill me in on them? What's the difference on how they are made, how do they compare to DLP's and plasmas? My friend is looking into purchasing a sony grand wega 50inch LCD and wanted to know some infomation on them. I've read that they have a bad grey scale and their black's are bad. Could you explain why? Thanks, Jon
     
  2. Allan Jayne

    Allan Jayne Cinematographer

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    Liquid crystals are not all that opaque in their darkest condition. This results in not too good blacks.

    A LCD RPTV has three postage stamp (or film frame) size LCD panels through which a projection lamp beams its light using a system of mirrors and prisms, and red, green, and blue cellophanes.

    A direct view LCD TV has a full sized LCD panel with red, green, and blue stripes comparable to a CRT screen, and a fluorescent back light.

    LCD's may also exhibit smearing of fast motion because it takes time for the crystals to change from transparent to opaque or vice versa.

    LCoS (liquid crystal on silicon) is similar to LCD except that the crystals are on a mirror and the light beam reflected off the mirror has to go through the crystals twice, giving an improved contrast ratio.

    Because the LCD panels are so much less expensive than DLP panels, there is one for each color (R,G,B) in an RPTV, no color wheel is needed and the rainbow flashes people associate with DLP are not a problem with LCD.

    Video hints:
    http://members.aol.com/ajaynejr/video.htm
     
  3. Jon Cheung

    Jon Cheung Stunt Coordinator

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    Awesome, thanks for the input. Since LCoS tv's have to go through the crystals twice, does that mean there will be smearing as well since the time is doubled? Is their picture better than LCD's? Are there other Tv's that would be incomparison to the Sony Grand Wega 50inch LCD for the same price? Thanks.
     
  4. Michael TLV

    Michael TLV THX Video Instructor/Calibrator

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    Greetings

    Bad grayscales compared to what? CRT RPTV's? Not really ... about the same if not slightly better overall after calibration.

    Regards
     
  5. Andrew Grall

    Andrew Grall Supporting Actor

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    Michael and others,

    How do you think the current crop of RP LCDs

    Hitachi 60VS810
    Sony 60XS955

    compare to the current crop of DLPs and DILA sets?

    Mits 62725
    Tosh 62HM(X)82
    JVC 61Z585

    I bought a JVC 61Z585, but it has been out of stock forever. The store gave me a Samsung 5663 for while I am waiting, and so far I have been fairly happy with the DLP technology...

    Any thoughts from a professional calibrator? [​IMG]
     
  6. Allan Jayne

    Allan Jayne Cinematographer

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    Given the speed of light, the LCoS technology does not have any more smearing compared with LCD due to the time it takes for the liquid crystals to change, all other things being equal.

    You can get a good gray scale with LCD. You would probably prefer to have the room not quite so dark with LCD compared with DLP and CRET since in a really dark room the fact that LCD "black" is not all that dark will be more obvious.
     
  7. Jon Cheung

    Jon Cheung Stunt Coordinator

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    So for the money LCD is worth it? The only thing that people can see negatively towards an LCD is the black? Is there anything else I should be concerned with before telling my friend to go ahead on purchasing an LCD tv? Thanks.
     

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