Square-box CRT vs. flat-panel LCD
LCD monitors were once the pride of professional day traders and well-heeled executives. Today, the technology has improved, and prices for small, 15-inch displays have dipped to about AU$600. That low price point makes sleek flat-panels a viable alternative to standard CRT monitors, whose technology has undergone few fundamental changes since Philo Farnsworth patented television in 1930.
| Terms you should know |
| Resolution: the number
of pixels in the whole image. For example, a resolution of 1,280x1,024 pixels
means that 1,024 lines are drawn from the top to the bottom of the screen,
and each of these lines is made up of 1,280 separate pixels.
VGA: video graphics array, equal to a resolution of 640x480 pixels SVGA: super video graphics array, equal to a resolution of 800x600 XGA: extended graphics array, equal to a resolution of 1,024x768 UVGA: ultra video graphics array, equal to a resolution of 1,280x1,024 display area: the measurement taken diagonally from one corner to the opposite corner (the same way it's done for TVs). CRTs include the outer frame, or bezel (which typically adds an extra inch) in the measurement; for LCDs, the viewable screen area is measured. footprint: the amount of space a monitor takes up on your desk |
Not that LCD monitors can compete with tried-and-true CRT monitors on price alone. You'll find wide variance, but 15-inch LCD monitors tend to sell for about the same as 19-inch CRT monitors on average. However, money isn't everything. In order of importance, here are the top five numbers to look at when choosing between LCD and CRT:
Dimensions. A slim profile has traditionally been the main justification for getting an LCD monitor. A typical 17-inch CRT monitor is a 17-inch, 35-pound cube. Although the stand for a 17-inch LCD monitor might be 9 or 10 inches deep, the panel itself measures just a couple of inches thick, and the whole assembly typically weighs less than 20 pounds. Just ask yourself what would fit better on your desk: a bulky microwave oven or a butcher-block cutting board standing on edge, and you'll start to see the allure of the LCD.
Refresh rate. Measured in hertz (Hz), low refresh rates on a CRT result in annoying flicker. You won't find a refresh rate specified for LCDs, mainly because flicker isn't an issue. (Flicker is caused by the scanning pattern of a CRT's electron gun, which LCDs don't have--the pixels are either on or off.) While almost all modern CRTs run at 75Hz or higher at any resolution you're likely to use--too fast for flicker to be noticeable--LCDs are simply easier on the eyes than CRTs.
Colours. With LCD monitors, there's a hard limit on colours, typically 16.7 million (also known as 24-bit colour). CRTs have no such limit, which in itself is no big deal since few applications go beyond 24-bit colour. The real difference is in colour accuracy, a quality not reflected in manufacturer specs. CRT monitors far outperform LCD monitors when it comes to colour. A graphic designer, for example, wouldn't touch an LCD monitor. Colours on any kind of monitor are created by varying the intensity of red, green, and blue dots in the millions of triads that make up an image. CRTs control colour by varying the intensity of the electron beam as it strikes each colour dot. To vary the transmission of light through colour filters, LCDs use magnetic fields to twist particles floating in a liquid--an inherently less precise process.
Response time. LCDs are slower than CRTs. Typically, it takes 20-50 milliseconds (ms) for an LCD pixel to respond, while it takes a CRT 8-12ms. The difference shows up in DVD movies, where fast-moving objects--particularly dark objects across a light background--may leave a slight trail of ghost images on an LCD. If you plan to do a lot of movie viewing or video editing, get a CRT monitor.
Power consumption. LCD panels draw less than half the power a CRT does. If you're buying a bunch of them, a 50- or 60-watt difference per monitor can add up to serious money over time, especially if your utility rates are high.
Behind monitor numbers, there are always intangibles. For example, though the contrast and brightness of LCDs now approach those of CRTs, the latter generally handle environments with excessive ambient light better. On the other hand, many people feel that text looks sharper on LCDs than on CRTs--one reason 17-inch LCDs are typically run at a crisp 1,280x1,024 resolution and 17-inch CRTs at a more pedestrian 1,024x768. And the coolness factor? LCDs win, hands down. They're sleek, lightweight, and so stylish they've almost completely displaced CRTs from executive desktops.
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