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Seven LCD monitors compared

Pixels never looked so good

IDC IS PREDICTING manufacturers will ship more LCD screens than traditional CRT displays this year. That feat is especially remarkable given the fact LCDs have notoriously poor pixel response times, resolution scaling, and contrast ratios when compared with traditional CRT displays. Don't forget that, inch-for-inch, LCD screens typically cost twice as much as traditional CRT monitors, too.

Why, with all those faults, have LCDs become so popular? Maybe it's lust. Consumers could be turned onto LCD panels because they have more sex appeal than CRT monitors. Maybe it's all about body image. LCD screens are thinner and lighter than CRT monitors, and I hear they have fewer carbs, too. Maybe it's the fact some users can't stand to go back to CRTs after basking in even a moment of the glorious brightness and clarity of typical LCD screens. Whatever the motivation, LCDs are wildly popular.

Thus, we've whipped up a seven-way LCD comparison to commemorate what may turn out to be the year of the LCD. Read on to find out which screen is most likely to tempt you away from that trusty CRT.

Revisiting the good, the bad, and the ugly
Although it's been almost a year and a half since we last looked at LCD screens, the display technology hasn't changed dramatically. LCD screens still use liquid crystal panels to manipulate light generated by a backlight. As they're stimulated, the liquid crystals change their molecular structure to allow light to pass through red, green, and blue pixel components. These pixel components are bound to individual transistors, giving each pixel dedicated circuitry.

Back-lit liquid crystal panels are quite different from the cathode ray tubes that power more traditional CRT displays, but the two technologies are generally capable of producing comparable on-screen images. However, due to differences in how CRTs and LCDs go about producing those images, each technology has its own strengths and weaknesses.

Since we're only looking at LCDs today, I've gathered the relative strengths and weaknesses of LCD screens below. This collection of The Good, The Bad, and The Ugly first appeared in an LCD round-up I did almost a year and a half ago, and the basic concepts generally remain true today.

The good
Where are LCD panels far superior to even high-end CRT displays?

  • Brightness - Though the relative brightness of LCD monitors varies quite a bit from manufacturer to manufacturer and model to model, LCDs are generally much brighter than CRT displays. Backlit LCD panels excel when it comes to generating vibrant images, and screens typically carry brightness ratings of twice as many candelas per square meter (cd/m2) as CRT monitors.

  • Image clarity - Though I can't break down image clarity to a metric measurement of goodness per square meter, the images and text generated by a properly configured LCD screen at its native resolution are incredibly crisp and clear. Part of the clarity comes from the fact that LCD screens are made up of a collection of static, clearly defined pixels. LCD screens with digital inputs also have a clarity advantage when used with DVI-equipped graphics cards because they bypass any digital-to-analog conversion.

  • Footprint - This one's simple: LCDs monopolize far less desk real estate than CRT monitors of the same size. The key here is depth; while LCD panels are rarely more than a few inches thick, the depth of CRT monitors is often their largest dimension. LCDs are also far lighter than CRT monitors, which makes wall mounting a breeze.

    Monitor footprint is less of an issue for those who are only running a single screen, but throw two or more CRTs onto a desk and things quickly get cramped.

  • Border width - While I'm on the topic of multimonitor setups, it's worth mentioning that some manufacturers are building LCD screens with very narrow screen borders. Narrow borders make it easy to create large virtual displays with a series of smaller screens, provided your system has enough video outputs to go around.

  • Power consumption - While CRT monitors can easily suck over 100W of power, but LCDs typically consume less than half that. For those looking to keep power consumption to a minimum, LCDs definitely have an advantage, and because the screens run on less power, they also generate less heat. Again, power consumption and heat output probably aren't going to be huge concerns for anyone running a single monitor, but a small office can get pretty sweaty with even a couple of big CRTs.

  • Reduced eye strain - Even high-end CRTs fed by strong video signals can produce eye strain after extended periods of use, but I find LCDs to be much easier on the eyes. This effect isn't always immediately apparent, because it generally takes hours for eye strain to manifest itself with a decent CRT setup. Spend extended periods of time with a CRT and LCD side by side, however, and I think you'll find the LCD is a heck of a lot easier to look at, especially when it comes to working with text.

The bad
Though LCDs have numerous benefits over traditional CRT monitors, it's not all roses.

  • Pixel response time - LCDs change their display images by altering the molecular structure of liquid crystals—a process that's far from instantaneous. Because panels rely on these lethargic molecular changes, LCD pixels respond much slower than CRT monitors. Pokey pixel response times can produce ghost-like afterimages that blur or streak fast-moving objects as they travel across the screen.

    The majority of today's mid-range and high-end LCDs claim pixel response times around 25 milliseconds, which means pixels can update themselves a maximum of 40 times per second. The equivalent of 40 frames per second should be fast enough for the vast majority of PC users, and even for casual gamers. If that's not fast enough for you, LCDs are available with pixel response times as low as 16 milliseconds.

  • Viewing angle - Though the images generated by LCDs are bright and vibrant when viewed from directly in front of the screen, they don't look so hot when viewed from above, below, or either side of the display. When viewed from more extreme angles, LCD displays lose a lot of their brightness, and colors begin to fade.

  • Color reproduction - Few LCDs can correctly produce all 16.7 million colors typically associated with 32-bit graphics. Properly calibrated LCDs should be able to produce enough shades of red, green, and blue to satisfy most users. However, graphic designers who really need a broad spectrum of colors are likely to be frustrated by the limitations of some LCD displays.

  • Contrast ratio - While brightness is definitely a strong suit for LCD monitors, their contrast ratios could use a little help. Since an LCD's backlight is always on (at least when the monitor itself is turned on), the display's liquid crystals must completely block light from the backlight in order to produce a true black. Unfortunately, few LCD monitors are up for the task, and many struggle to produce darker shades of other colors, as well.

The ugly
If The Bad has turned you off LCDs already, The Ugly can definitely vindicate your decision.

  • Dead pixels - Each of an LCD's pixels is a separate entity with its own color components and dedicated circuitry. If a pixel's circuitry is defective or fails prematurely, the rest of the screen can carry on as if nothing had happened. In fact, a screen can often survive multiple pixel fatalities. Unfortunately, once a pixel dies, there's no way to bring it back. Dead pixels remain frozen on either white or black, which can get really annoying, really fast. The fact that screens often don't quality for warranty replacement until at least five pixels have failed isn't much help, either.

  • Resolution scaling - Because LCD panels have a fixed number of discrete pixels, they're really only designed to display a single resolution—the screen's native resolution. LCDs can't display resolutions above their native resolution, and can only display lower resolutions through interpolation, which stretches smaller display resolutions to fit an LCD's native resolution. Except in rare cases where a screen is stretching a resolution that's exactly half its native resolution (800x600 for a native 1600x1200 display, for example), interpolation is pretty ugly. Generally, scaling completely ruins the image clarity advantage LCDs usually enjoy.

    Interpolation is really only an issue if you need to run a screen outside its native resolution, and that's pretty rare unless you play games. Gamers will have to live with interpolation unless their systems are capable of churning out reasonable frame rates at their LCD's native resolution. Doing so shouldn't be too hard for older games like Quake III Arena, but the hardware requirements for churning out reasonable frame rates in new games like Doom 3, even at medium resolutions like 1024x768, will probably be pretty steep.

  • Cost - If The Good still outweighs The Bad and The Ugly, you have to ask yourself by how much, because LCD screens carry a hefty price premium over CRT monitors. Typically, LCD screens cost at least twice as much as a CRT monitors of equivalent size. Good luck justifying that to your boss or significant other. To be fair, LCD prices have fallen quite dramatically over the years, but so have the prices of CRT monitors.