How to interpret subpixel array images?

Discussion in 'Hardware Components and Aftermarket Upgrades' started by slurpy, Jul 30, 2018.

  1. slurpy

    slurpy Notebook Enthusiast

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    Most of the reviews posted by reviewers at notebookcheck include images of the subpixel array for the laptop's display. What should be looked for in these images for evaluating the quality of the display?
     
  2. jeremyshaw

    jeremyshaw Big time Idiot

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    Mostly, whether or not there is aggressive anti-glare (not really an issue nowadays - the days of super aggressive anti-glare are long over, save for very niche applications).

    To a lessor extent, make sure there is an RGB array. Red, Green, & Blue. Not some other layout like RG BG, RGBW, or any other Pentile-style layout. Almost always (not 100%, but nearly 100% of the time), it's used to lie about resolution. Instead of a full supixel array (RGB) per pixel, there are "shared" subpixel arrays.

    For example:
    RGB = 1 pixel
    RG BG = 2 pixels
    RGBW = 2 pixels.

    The proper layout has all three primary light colors (RGB) per pixel. The cheating layouts only have two colors per pixel, and they dither/diffuse/etc with a neighboring pixel to get the "full" color array. In practice, this means the manufacturer can remove ~33% of the subpixels from a "full RGB pixel" to make a "high resolution" display. However, this means the actual resolution is overstated by up to 33%. In an example I am personally familiar with, a "1280x720" RGBW display has only enough subpixels to really make a ~840x480 RGB display. But 1280x720 sounds more impressive on a spec sheet than 840x480. This applies even to 4k ultraHD resolutions - not all displays actually have "4k resolution."

    Why this matters is the non-RGB layout often have a bit of subpixel rendering problems when displaying fine details or displaying black text on a white page. Not all RGB layouts are perfect, but all of the "cheating" layouts are flawed by design. There are a few niche applications for them, but none in computers.
     
  3. slurpy

    slurpy Notebook Enthusiast

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    Thanks for the info. How did you learn about this?
     
  4. jeremyshaw

    jeremyshaw Big time Idiot

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    @slurpy
    No problem!
    I started down the subpixel path by buying a Pentile "HD" display and wondering why it was worse at displaying text than my old "SD" display. I had known a little bit from digital photography, but not much.

    The rest is from people shouting over the internet about how anti-glare or glossy made their kids go blind, their eyes dry, and seared their retinas with the fury of a thousand suns.
     
    alexhawker likes this.

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