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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  • nullpointerus - Friday, December 3, 2004 - link

    So you mean that only _some_ LCD's with that resolution are physically 5:4? LOL, I just couldn't resist it. Sorry I missed your previous post!
  • GOSHARKS - Thursday, December 2, 2004 - link

    As I had previously stated (#61,62) - ALL computer LCD's with a resolution of 1280x1024 are PHYSCIALLY 5:4. You will not find a 1280x1024 LCD on the market that is physically 4:3. Kristopher Kubicki really needs to address this in an amendment to his article.
  • nullpointerus - Thursday, December 2, 2004 - link

    Keep in mind now that most cards are dual-capable, you could keep your CRT for games and get the LCD for word processing - to decrease eye strain. Not only that, but you could watch TV on the CRT while you're working, or keep two documents visible at the same time, etc.
  • archcommus87 - Thursday, December 2, 2004 - link

    Thanks for the info.

    That's a major turn off for any LCD for me, then. I wouldn't mind running my desktop in 1280x1024 if the monitor itself had a 5:4 ratio, but having to scale my games or run them in a smaller screen would annoy me. Right now I run HL2 in 1280x960 plenty smoothly, but I won't necessarily ALWAYS be able to run the newest games in that high of a resolution.
  • nullpointerus - Thursday, December 2, 2004 - link

    Oh, I might also have mentioned why LCD's are different than CRTs.

    A LCD produces its image via millions of fixed-size, fixed-position cells that are manipulated with some kind of electrical charge to produce colors which collectively form an image. When the image size isn't exactly the same size as the number of cells, some algorithm has to be applied to scale the image up/down before it can be displayed. There's no physical distortion, but you may get stuck pixels, gamma problems, and streaking.

    A CRT produces its image via an electron gun which continually blasts the screen with lines of colors (basically) y*r times per second, where y is the vertical resolution and r is the vertical refresh rate. The size, shape, etc. of these lines are configurable so they can be very easily stretched and manipulated without by changing the focus and interval of the beams. So there's no scaling algorithm per se, but then again you get convergence problems (i.e. where the RGB beams go out of sync with one another), physical distortions (i.e. rounded/skewed/pincushioned image).

    That's why LCDs have a "native" resolution while CRTs just have a kind of a maximum firing rate which is usually referred to in terms of a "pixel clock." So in a sense you could say that all of a CRT's supported resolutions are "native."
  • nullpointerus - Thursday, December 2, 2004 - link

    archcommus87:

    1. It depends on the LCD in question, methinks. Some searching for specifications by the model number of the LCD that you are searching for will usually turn up its aspect ratio. Try to corroborate information from several sources (especially the manufacturer's website if possible) since the stores can get the specs wrong.

    2. LCDs run in their native resolution. If that's 1280x1024, it will always "run in" 1280x1024 no matter what resolution your video card is feeding it the video data. There are several ways that lower-than-native resolutions can be handled, depending on your video card's drivers.

    AFAIK, the default way is to simply use monitor scaling. For example, if you run a game at 800x600, your flat panel will extrapolate this up into an 1280x1024 image, which makes it look rather blurry. Scaled graphics will probably just look "different," but scaled text will appear fuzzy.

    There's also cropping, which will just use the center 800x600 pixels for example and set the others to black. So you get a smaller picture than if you had let the monitor scale it up, but on the other hand it will also be clearer. This might also be called "centering."

    IIRC, nVidia has more options in this respect than ATI, but that might depend on the model of your card as well. Maybe look in your video driver help files or ask around to see what your video card supports.
  • archcommus87 - Thursday, December 2, 2004 - link

    No one has provided a clear answer on this, can someone please do so?

    We know 1280x1024 is 5:4. So are the LCDs actually 5:4 in physical size or are they 4:3 like a CRT? I keep hear differeing opinions. Or is each brand different?

    Second, how do LCDs respond when you change the resolution to something other than native? Does everything look garbled and crappy or is it okay as long as you keep your ratio? The reason I ask is because if I had a 19" LCD running at 1280x1024 resolution, I don't think I'd *always* want to run my games at that high of a res.
  • comomolo - Thursday, December 2, 2004 - link

    Hey, Anandtech, I usually trust your reviews, but should I read further when you state that 17 and 19 inches monitors put 5:4 aspect ratios into 4:3 boxes? Or when you compare CRTs capable of much higher resolution than that of the 17 and 19 inches LCDs. An apples to apples comparison would show you LCDs are still much more expensive than comparable CRTs.
  • Toadster - Wednesday, December 1, 2004 - link

    why no review of the DELL 1905? i mean, DELL reigned in the 20+ review why not the 19?
  • deathwalker - Wednesday, December 1, 2004 - link

    The Dell 2001FP is only $799 for those that don't shop smart..I bought mine several weeks ago and only paid $639 for it. I love it and have no regrets even after this article. Im runnin a 1600x1200 desktop..something none of these other monitors can do.

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