How to Pick a Good LCD (continued)

Color Depth: Almost all LCDs today are 6-bit or 8-bit LCDs. This means that each subpixel - Red, Green, and Blue - can display one of 2 to the n shades where n represents the number of pixels. A typical 8-bit LCD can produce 256 shades per pixel, or 16.7M color combinations. A 6-bit LCD panel can display 64 shades per subpixel, and since there are three subpixels per pixel, the monitor can display 262,000 color combinations per pixel. This is generally OK for gaming, but certainly not acceptable for any graphics development. Personally, I enjoy seeing the other 98% of the 24-bit color spectrum.

Brightness: Brightness is fortunately an easy specification to remember. More is better, particularly on LCDs with higher resolution. Even though your LCD might have six bulbs behind the substrate, a very small fraction of that light actually filters through the liquid crystal. Although, the measurement of "candela per meter squared" or "cd/m2" or "nits" all refer to the amount of light that actually passes through the front of the monitor at a 90 degree angle.

Viewing Angle: Viewing angle generally has a lot to do with the display mode of an LCD. You may wish to check out our LCD FAQ from a year ago that went through a lot of the basics of LCD design, particularly the pages on how LCD substrates work. Differing display modes utilize differing methods for twisting the LCD crystals - TN, PVA and SIPS are just a few. When LCDs were new, there were large issues with getting light to pass through the substrate at more angles than just 90 degrees head on, and for a short period of time, it was important that LCDs have some viewing angle. However, almost all LCDs today (and for the last 3 years or so) have viewing angles that are wide enough for anyone to look at the LCD from any (sane) angle. Unless you spend a lot of time looking at your monitor from 3 feet away, 60 degrees off center and at a 45 degree incline, don't worry about viewing angle so much when buying an LCD. We generally only mention viewing angle in our reviews if something seems amiss.

Contrast Ratios: Contrast measurements were originally supposed to quantify the difference between the lightest light and the darkest dark on the LCD. For example, if a black portion of the screen has a brightness of 0.5 cd/m2, and a white portion has a brightness of 250 cd/m2, then the monitor would have a contrast level of 500:1. Almost immediately, this measurement has been abused; manufacturers can take these measurements on angles to assure darker darks and brighter brights. Furthermore, other manufacturers take these measurements in different light settings and with different test pattern (some take measurements with the screen completely dark, while others take measurements with the screen in a checkerboard pattern). Unfortunately, relying on manufacturer Contrast Ratios too heavily during a purchase will probably lead you astray. To correct that, we will run a standardized test in our lab that tests contrast ratios of all of our LCDs in controlled situations.

So far, we covered only the introductory basics in shopping for an LCD. Footprint, features and rotation capabilities are all important as well, but don't be awed by monitors with features that you will never use. Paying $50 extra for MagicBright or a TV tuner only makes sense if you're going to use it.

How to Pick a Good LCD Buying an LCD
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  • benk - Tuesday, November 30, 2004 - link

    I just (like two hours ago) got my Dell 2005FPW...played an hour of CS:S. Didn't notice any ghosting, blacks were all black, etc. I have my desktop set up stretching across this LCD and my old Sony Trinitron 17" and the color and sharpness on the LCD is markedly better. It actually surprised me; I thought I was giving up color in trade for a wider monitor that's a little easier on the eyes. Nope. It looks great, plays great, and, according to my girlfriend, is lots more stylish.
  • IceWindius - Tuesday, November 30, 2004 - link

    Screw LCD, SED is the wave of the future.

    Until then, i'll stick with my Viewsonic CRT monitor, thank you.
  • archcommus87 - Tuesday, November 30, 2004 - link

    Can anyone go back to the issue that someone asked prior about running non-native resolutions? My biggest deterrent about LCDs was always the fact that if I run my desktop at 1280x1024, I have to run all of my games at that, too. Sorry, but unless I'm buying two video cards a year, that's sometimes hard to do.

    Can you use other resolutions without getting crappy images?

    Yes, at times I have considered selling my 19" and 17" CRT dual monitor setup for one, single 19" LCD. But then I think, nah I love my Philips, and two monitors is cool. Plus I'd hate to have to run all my games at such a high res.
  • nullpointerus - Tuesday, November 30, 2004 - link

    Cat: The lower the refresh rate on the video card, the more sluggish the mouse feels to me. Anything below 75 Hz feels terrible. Setting it up to 100 Hz (assuming your card and display support it) feels extremely fluid. I'm just suggesting possibilities, so YMMV.

    TCfromNL: From what I can tell, the article doesn't make any such claims about whether you have problems if the GIF appears dithered on your display; it's just presenting a visual aid.
  • coldpower27 - Tuesday, November 30, 2004 - link

    It depends on each peoples eyes, I guess it's not quite as noticable to some. Also not all the 25ms screens are created equal.

    I have a 25ms LCD, and I don't really notice ghosting, I got it over 2 years ago, though when it cost alot. Though 25ms for an LCD to do continous motion as that enough to generate 40FPS, I also don't really play that many FPS. The new LCD's that are capable of 12ms are amazing that like double the FPS at maximum.

    Yeh it would have been nice to test some of the newer LCD panels as well, but to me I don't know why people want it so bright, my LC is around 350:1 range and I already fine that awfully bright, 800:1 just seems so much :S
  • drinkmorejava - Tuesday, November 30, 2004 - link

    I'm confused, how can all those 25ms monitors have no noticeable ghosting. I've always known that a black-white measurement does not truly show how much ghosting there will be, but a 5?
  • TCfromNL - Tuesday, November 30, 2004 - link

    Okay. Small problem with the 256-shades-of-blue thing, referred to as "the image below".

    Since it's a GIF, it only contains 256 shades of color, tops. Including all the greys.

    I imagine you have a losslessy (or un-)compressed 24-bit copy somewhere. Still, it's not nice to scare your readers by displaying some 20-shades-of-blue thing while saying that if it doesn't display smooth as a baby's skin, which it doesn't, the viewer's monitor is at fault.

    Further, nice article. But since these monitors are all 1280x1024 (except for the 20" Dell), I can't help but leave disappointed. I don't like squarish monitors. There's a reason why TV evolved from 4:3 to 16:9. I agree with the cry above: IT DOES NOT MAKE ANY SENSE.
  • gwynethgh - Tuesday, November 30, 2004 - link

    Now to find a good but reasonably priced DVI KVM switch.
  • KristopherKubicki - Tuesday, November 30, 2004 - link

    Klah: have they benchmarked any units using that methodology except the example? I checked around and couldnt find any.

    Kristopher
  • klah - Tuesday, November 30, 2004 - link

    "klah: I was only aware of Xbitlabs doing so. We feel that the methods for measuring reponse time thus far are OK, but not represent gray to gray response time measurements well. Its something we are working on and we will probably have a better methodology before the next roundup.

    Kristopher"

    Here is Tom's methodology:
    http://graphics.tomshardware.com/display/20040923/...

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