Today we've rounded up a total of seven different LCD screens from the likes of Hercules, KDS, Philips, Samsung, and Solarism. Each display has its own unique feature set, aesthetic, and performance quirks that vary more than you might expect. As we weave our way through all seven screens, we'll also serve up some general observations on common LCD performance characteristics, and the pros and cons of the genre as a whole.
LCDs have come a long way since their appearance in early laptops, where even rendering a moving cursor was a problem. We've run these screens through basic desktop tests, DVD playback, slow- and fast-paced gaming, and even a suite of synthetic monitor test programs. Which LCD comes out on top? Let's have a look.
A few notes on LCDs
Before we dive into the performance and features of the individual screens, it's a good idea to take a quick look at LCD monitors in general to find out what makes them tick. Overall, LCDs tend to perform exceptionally well in some areas, and rather poorly in others. The benefits and detriments are a result of the way LCD technology itself works, so there are some traits that all LCD monitors will exhibit to varying degrees.
Most current LCD-based monitors are active matrix displays, often referred to as TFT (thin film transistor) LCD screens. LCD, of course, stands for Liquid Crystal Display. Liquid crystals are stimulated to change their molecular structure, and in doing so, are able to manipulate how much light passes through the display screen. A backlight provides the initial illumination, which the LCD screen then manipulates, passing light out through the red, green, and blue components of its individual pixels.
Unlike CRTs, LCDs actually have individual circuitry corresponding to each pixel of the display. The pixels themselves contain red, green, and blue components just like you'd find on a CRT, but each color component is bound to a transistor.
To the human eye, LCDs are capable of producing roughly the same image as a traditional CRT monitor. In certain situations, LCDs can look a lot better than CRTs, but in others, then can look a lot worse. Here, I've broken things down Eastwood style.
In some ways, LCD monitors are vastly superior to even the best available CRTs. How?
- Brightness - LCDs are bright. Really bright. Depending on the brightness of the backlight and how well the display's liquid crystals can align to pass all available light through the screen, many LCDs are capable of being just short of blinding if you crank the brightness. (Finally, a less embarrassing excuse for your computer-induced blindness!) But seriously, LCD screens are typically at least twice as bright as CRT monitors, something that's especially noticeable in darkness, when a light background can really brighten up a room.
- Image clarity - "Crisp" is probably the best way to describe the images typically produced by LCDs. Text looks simply gorgeous, especially with Microsoft's ClearType turned on. Part of the reason why images look so good on LCDs is the individual pixel circuitry, but some credit also has to be given to displays with digital interfaces that do away with messy analog-to-digital conversions, provided your graphics card is capable of putting out a digital signal.
- Footprint - Take a look at how much of your desk is currently taken up by your monitor. Seems like a lot, doesn't it? CRT monitors are notoriously big, bulky, and deep. LCDs are the exact opposite; many are just inches thick, if that, and some even come with wall-mounting hardware. Because of their size, LCDs are also much lighter than CRTs, which makes lugging them around a lot easier.
- Power consumption - CRT monitors can easily consume well in excess of 100W of power, and in doing so, produce a lot of heat. LCDs, however, typically consume less than 50W, and can be much cooler as well. The drop in power consumption is certainly attractive, especially for businesses with cubicles full of workstations. Though it might seem like an afterthought, heat output can also be a big deal; just ask anyone who's been to a cramped LAN party filled with CRT monitors.
It's not all good. Here are a few of LCD technology's shortcomings.
Pixel response time - The liquid crystals in an LCD have to change their molecular structure to manipulate light, and that's not a speedy process. As a result, LCD pixels respond much slower than what you may be used to on a CRT monitor, and that can cause ghosting and streaking, especially at high frame rates.
The pixel response time of LCDs has improved dramatically over the years, but CRTs still have the edge. What's most worrying about pixel response times, however, is that LCDs with similar pixel response time specs don't always show the same performance in the real world. It's really something you have to check for yourself.
- Viewing angle - When viewed from the side, above, or below, images on LCD monitors become noticeably darker, and colors start to get washed out. CRTs, on the other hand, can be viewed from extreme angles with little loss in actual picture quality. Admittedly, there are few areas where viewing angle makes a big difference for end users, but the limitation is worth noting. If, for example, you want to watch a DVD on your LCD with a group of friends, everyone is going to have to get real cozy with each other on the couch to see things properly. Limited viewing angles might not be a bad excuse to get a little closer to your date, but your buddy that's just over to watch Office Space may object to you rubbing up against his leg like that.
- Color reproduction - Although LCD screens claim support for 32-bit color, the displays themselves often aren't capable of accurately reproducing all 16.7 million colors common 32-bit graphics modes. With a properly calibrated LCD, a casual user probably won't notice the difference, but the limitation will probably give graphics designers fits.
- Contrast ratio - LCDs are back-lit whenever they're on, which means that TFT panels have to orient the liquid crystals to block light if they want to display black. Some light inevitably manages to seep through the cracks, which limits a screen's ability to display a true black.
Along with the bad come a few show-stopping limitations for LCDs.
Resolution scaling - A TFT LCD monitor's maximum resolution refers to the actual number of pixels present on the display. An LCD is really only designed to be run at one particular resolution. If you try to display something at a resolution of 1024x768 on a screen with a maximum resolution of 1280x1024, the display will actually stretch your 1024x768 image over the full 1280x1024 pixels. Stretching requires interpolation, which inevitably degrades image quality, especially noticeable when displaying text. (CRTs, by contrast, are capable of syncing to multiple scan modes and showing multiple resolutions natively.)
One minor area where resolution scaling doesn't exhibit problems is perfect geometric scaling. If, for example, you had an LCD screen whose maximum resolution was 1600x1200, you could display images at 800x600 without experiencing the detrimental effects of image stretching. Because 1600x1200 is exactly four times the resolution of 800x600 in terms of the actual pixels required, a 1600x1200 display simply uses four pixels to represent a single 800x600 pixel.
Dead pixels - The bane of every LCD's existence: the dead pixel. Remember how each pixel on an LCD has its own transistors? Defects and/or premature failure of those transistors results in dead pixels, which can appear as solid white or solid black. There's no way to resurrect a dead pixel. It's gone, and there's no sense mourning. Depending on the manufacturer, a certain number of dead pixels will qualify you for warranty service, but you'll have to suffer with the random dots until you hit that magic number.
Monitors with dead pixels can sometimes slip through QA and make it to store shelves. The issue of dead pixels makes buying a monitor online, unseen, a little more risky than usual.
Cost - When you consider their shortcomings, the fact LCDs cost so much is rather shocking. Generally, you can get a good 21" CRT monitor for the same price as a decent 17" LCD screen, which makes LCDs a tough sell, period. Start getting into multi-monitor configurations, and the total cost only spirals higher.
In time, LCD prices will drop, but CRTs have a huge head start. The good will have to really outweigh the bad and the ugly if you want to justify an opulent LCD purchase to your boss, to yourself, or worse, to your significant other.