LCD and black levels

Discussion in 'LCD & LED LCD TVs Forum' started by djcla, Mar 7, 2006.

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  1. djcla

    djcla
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    How do they reproduce black's because from a few that i have seen , black just seems to be jet black and looks almost as if the pixel is turned off. There does not seem to be any levels of black reproduced is this correct or am I completley off the mark?
     
  2. chambeaj

    chambeaj
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    How It Works: LCD Monitors
    http://www.pcworld.com/howto/article/0,aid,15112,00.asp
    [​IMG]

    How LCDs Work
    http://computer.howstuffworks.com/lcd3.htm

    Liquid crystal display television
    http://en.wikipedia.org/wiki/Liquid_crystal_display_television

    Liquid crystal display
    http://en.wikipedia.org/wiki/Liquid_crystal_display#Active_matrix_technologies

    TFT LCD
    http://en.wikipedia.org/wiki/TFT_LCD
     
  3. andrewfee

    andrewfee
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    The reason LCD blacks look so good in stores is because they are in brightly lit environments.

    An LCD works by shining a light through the LCD itself, and the brighter the ambient light, the more of a "cancelling" effect it has. With a bright enough light, LCD blacks look jet black, yet are still full of detail.

    In a home environment, in a darker room, blacks can be much less impressive. If the ambient light in your home isn't as bright as the backlight (which seems to be getting brighter with each new set released) then it will be noticeably brighter than black.

    However, many sets compensate for this by allowing you to lower the backlight brightness to better suit the environment it is in. Sony LCDs are particularly good for this, as they have a "power saving" mode that drops it right down. Even in a room that is almost pitch black, their LCDs still produce extremely convincing blacks compared to other models.
     
  4. LV426

    LV426
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    I'm not sure we're answering the question. I picked up particularly on this bit:
    which I'm interpreting as a question about "crushed" blacks.

    And the answer is - it's all down to adjustment. In order to make TVs look "good" in stores they tend to have a preset set of adjustments wich may be called "dynamic" or something similar, which tends to try and make the image look exciting at a quick glance at the expense of black level detail and possibly white level detail too.

    Get one home and immediately set up your own preference, ideally using a setup disc or failing that, the THX Optimiser on some DVDs and you will get all the detail you need.
     
  5. andrewfee

    andrewfee
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    Ah; if that's the case, then the brightness is set too low for the current viewing conditions. You ideally want the backlight set low enough to produce pure black (or as close as possible) as you can, and then set the brightness high enough to see all the detail.

    Again, both settings vary based on ambient lighting conditions.
     

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