IntroductionWhen we ran the LCD flat-panel round-up a couple of years ago, prices were in freefall – so much so that it seemed possible most future displays made would be LCDs – and that traditional CRT (Cathode Ray Tube) displays were on the way out. However, soon after that feature, prices again started climbing, and soon, flat-panels were prohibitively costly. Well, it’s déjà vu all over again – as Big Ron would say – because LCD displays are better and more affordable than ever. This is great news for everyone bar hard-core designers, who are likely to stick with CRTs come what may because of their superior colour fidelity. LCDs can fall down on colour-critical work because the viewing angle affects the colours displayed. However, with good hard-copy proofing, there’s no reason at all why a decent-quality LCD can’t figure in professional workflow situations. Figuring what constitutes quality in an LCD monitor is a tough task for the uninitiated, because LCD displays are still relatively uncommon compared to CRTs. For this Test Centre, we secured 26 models from 15 manufacturers. We tested them head-to-head to determine which ones most successfully produce the best blend of price and performance. Digital or analogue?
Unlike CRT monitors, LCD screens are digital rather than analogue. Until recently, most computers had only analogue output to control CRT monitors. Now, desktop Macs have acquired a digital output, but in a format incompatible with most digital screens – except, of course, Apple’s own. This isn’t an insurmountable problem, as there are adaptors available, but it adds another level of complication. While LCD screens are inherently digital, they usually sport an analogue connection so that they’re compatible with the majority of computers. This year, more screens than ever offer both a digital and analogue connection. Flicker of hope
Sorting out the wheat from the chaff is a little different for LCDs than for CRTs. For example, refresh rate – a good measure of the capabilities of a CRT monitor – is entirely irrelevant with LCD screens. Flat-panels don’t suffer from flicker, because the image doesn’t scan down the screen as it does with traditional monitors. Instead, it appears instantly. Once a pixel is illuminated on an LCD, it remains – as opposed to fading after the cathode ray has passed by. The result is a screen that remains flicker-free, even at miserly refresh rates of 60Hz. Resolution
Resolution is also handled differently in flat panels. There are a set number of pixels, and, although you may be able to display different resolutions, they must all be translated into the native resolution. This might work well enough with pictures, but text will always look bad if displayed at a resolution that isn’t the native one. If you are used to seeing icons at a particular size on a CRT, you may be in for a shock with an LCD. Because traditional monitors have variable resolutions, you can change this to suit your preference. If, however, you’re an early adopter of Mac OS X, then this is not a problem, as OS X allows icons to be resized to your requirements. The simplest thing to do is pay for the biggest screen-resolution you can afford. If your eyes aren’t up to looking at tiny icons, then go for a larger screen – or perhaps try out OS X. Size does matter
Screen size is one thing that is easier to understand with flat panels than CRT displays. With traditional displays, the size of the tube is what the model will be sold on – with the actual viewable-area size appearing only in small print. LCD displays give you only the diagonal screen-measurement, so only the viewable area is measured. When comparing LCD with CRT sizes, be sure to compare the viewable areas. A question of control
When a digital display has an analogue input, there will be some tweaking involved to line-up the image with the correct pixels. Without this tweaking, greys and fine vertical-lines can become noisy and distort text. Many screens have an auto-adjust feature to take care of this, although sometimes you can do a better job by doing it manually. Consequently, good adjustment controls – particularly for this feature – are important. Colour critical
Apple claims its screens are fine for high-end colour work, but only recently have there been tools to accurately calibrate LCD monitors. So, how do LCD screens compare to CRTs for colour accuracy? The theory that LCDs are better than CRTs for colour pivots on the fact that they’re much brighter. An uncalibrated LCD such as the Cinema Display has luminance of 180 candelas, compared with a CRT – such as the LaCie electron 22 – which outputs a white luminance of 158 candelas. The Barco range of CRTs are set to a conservative 75 candelas, though Barco claims to be able to hold this calibrated state for three years. Calibration by necessity lowers the raw output of a screen, be it LCD or CRT, and the Cinema Display was dramatically reduced in brightness to 108 candelas. The LaCie electron went down to 103 candelas, but, because the blacks on a CRT screen are darker than with an LCD, the contrast range is comparable. Contrast is pretty much the same, though blacks are a little dusty on LCD screens. Colour accuracy tests show the CRTs ahead on this score. Faithful colour-reproduction is still something that CRTs hold sway on. Colour is also less uniform on LCD screens than on CRTs, blighted by light and dark patches. This is because LCDs must be lit with a light source, while CRTs create the light and colour with the same light source. Quality on cheaper LCDs also suffers when viewing the screen from an angle, whereupon the colours change. It’s less of a problem with modern LCD displays, but can still make a difference with colour-critical work. Before you throw your hands up and your flat panel out, there’s another matter to consider. Are you one of the elite that regularly calibrates your monitor? If so, then you’re in a small minority that takes colour seriously. If, like most people, you performed an initial calibration with the Monitors Control Panel – and do so once a year – then the minor inaccuracies of an LCD screen will be no hardship for you. Lots of people seem to want colour calibration, but relatively few use it. So, unless you actually use calibration properly, don’t worry that LCD isn’t good enough for you. The price is right?
The price of LCD panels is as volatile as RAM prices. Presently, prices are as low as they have been – and analysts are widely predicting a further flat-panel price war. As with all volatile markets, you need luck when making a purchase: if you buy now, prices may continue to fall through the floor; if you hesitate, they may go through the roof. Additional features
There are important features with LCD screens that are not easily compared. For instance, the LG and the Samsung 15-inch screens have built-in TV tuners. This is fantastic if you want them, but useless if you work in a basement with no TV signal. Other more common bonus features include speakers and USB hubs. Speakers are always handy, although sound quality is unlikely to match a pair of good external speakers, such as harmon kardon’s SoundSticks. But compared to the Mac’s weedy internal speaker, it’s likely to be an improvement. A USB hub is a helpful feature. A two-port hub is just enough to connect a keyboard and mouse. If the screen houses a four-port hub, you’ll be able to connect extra gadgets, such as a Palm cradle or printer. Although a four-port hub costs only about £30, it does mean having more gadgets on your desktop. Having a hub built into your monitor keeps cable clutter to a minimum. Can your office justify the expense?
Although still pricier than CRTs, there are two good reasons why flat-panel displays are a good idea for offices. Heat output is one. A large CRT monitor can get pretty warm, and an office full of them will end up feeling like a sauna, unless the air-conditioning is cranked up. Flat-panel displays use up to 60 per cent less energy, making for a cooler office and considerably lower electricity bills. Space is another issue. A 22-inch CRT will swamp most desks, but even a big LCD screen leaves plenty of elbow room. An office full of LCDs can mean being able to fit more people into the same space – thus keeping the accountants happy.