IntroductionIf you're still using a CRT (Cathode Ray Tube) glass-screen monitor, there's a good chance that, when the time comes to replace it, you'll opt for an LCD (Liquid Crystal Display) flat-panel display - because for many users, LCD screens have fallen within their price range. However, flat panels aren't right for everybody, especially if colour accuracy for the purposes of on-screen proofing ('soft proofing') is important to you: even the hugely expensive top-end LCD models - used in conjunction with a hardware calibrator ? do not come close to being up to the job, being outperformed on colour accuracy by the far-cheaper CRTs. Here, we take a look at large CRT monitors because, for pros, bigger is better. All the monitors on test measure at least 21 inches diagonally, and have at least a 20-inch viewable area. This allows for resolutions of up to 1,600-x-1,200 pixels. In Mac OS 9 such a resolution rendered desktop icons and text small and difficult to make out, but Mac OS X allows for the resizing of icons. However, menu items and application palettes can't be changed - so at very high resolutions, these remain hard to see. A number of screens on test offer even higher resolutions, but these are often subject to lower refresh rates, and are impractical. What ultra high-resolution monitors do offer is higher refresh rates at lower resolutions - so reducing flicker. Given the amount of time we spend staring at our screens, reducing eyestrain is important. A factor that's also becoming ever-more important to with CRTs is aesthetics, a situation caused by the super-sexy design of LCDs such as Apple's Cinema Display. Such appealing designs are persuading many to opt for a stunning LCD rather than a clunky CRT. CRT vs LCD
Colour integrity on even the best LCDs is not uniformly reliable, because the screen image changes with the viewing angle - something that's especially pronounced with bigger screens, because the change in viewing angle from the top of the screen (eye level) to the bottom is greater. Despite claims to the contrary from LCD manufacturers, even a hardware LCD calibrator cannot alter this, because the sensor is placed directly onto the screen. Although calibrators do offer better LCD colour accuracy, colour still shifts when viewed from different angles: it's simply impossible for colours to appear identically to the eye at all points of the screen. This phenomenon plays particular havoc with images containing graduated tones, especially at the screen's extremities, where it can be hard to tell if these graduations are part of the design or merely unwanted screen effects. For those working on the Web or for television, calibration and colour accuracy is less important, because the screens of your audience are likely to be wildly uncalibrated - something over which you've no control. If you work in print, however, then colour accuracy is everything, and, to this end, the monitor is the most important tool in the workflow. Someday, light-emitting plastics (LEPs), organic light-emitting diodes (OLEDs) or vacuum-fluorescent displays (VFDs) may well take the place of LCD and CRT displays. But until then, CRT displays remain best for colour: they can be viewed from any angle with no colour distortion and offer the best method of soft-proofing images. There are drawbacks with CRT technology, though. One such fault is that CRT image-shape is not always as accurate as it should be. Because CRT monitors can handle multiple resolutions, the dimensions of the image can stray from the true shape. With LCD screens, the resolution is fixed; the pixels don't move, ensuring distortion-free images all the time. Flat hunting
The curved glass of older CRT displays caused additional problems with distortion. All of the models on test except the Barco use flat glass. Where curved screens tend to focus any light source onto a particular point of the screen, flat glass reduces reflections to a minimum. All CRT displays are not created equal. Despite many of them sharing the same tube - most, for example, uses Mitsubishi tubes - their electronics and plastics are often different. Even models that appear very similar can offer different features - whether it's a hood to reduce reflection, or optional colour calibration. Even when all the specifications are apparently identical there can still be quality differences. It's almost impossible to get to the truth about this: some companies that use rebadged OEM models claim that they get the pick of the crop on tubes, others that their machines are more finely tuned in the factory. The manufacturers would - I'm sure - dispute this. There's no way of knowing who's telling the truth. The fact is that the monitor market is mature, and all models offer fairly high quality. There isn't a great deal separating the top models on test. There are, however, other ways of evaluating a screen's worth. Many of the models in this feature ship with special software offering extra features. Unfortunately, much of this is for PC users only, leaving Mac folk to fend for themselves. Fortunately, Apple does include a useful software monitor calibrator with OS 9 and OS X 10. This helps give the user an idea of how the screen image should look, and will be enough for some graphics users. However, anyone who's serious about colour should buy a hardware calibrator. In the past, hardware calibrators were prohibitively expensive for many, but now there are a number of good and relatively cheap models. What matters
Measuring a monitor's abilities is difficult, because many specifications contribute to overall performance. To further complicate matters, a monitor can look good on paper but fail to live up to expectation, producing a green tinge or a wonky image, for example. The most-important performance indicators are maximum resolution and refresh rate. Resolution - Maximum resolution is likely to be much higher than you can realistically use. Maximum resolution isn't so much a boast about the massive range of available resolutions, but rather is a general demonstration of the monitor's capabilities: if a screen can display a resolution of 2,048-x-1,536 pixels, then lower resolutions will be well within its capabilities. It's a bit like driving a car with a top speed of 180 miles per hour - you'd rarely if ever hit that speed, but know that driving at motorway speeds will be a breeze. Driving a Smart Car at 70mph, however, would leave you feeling far-less secure. Refresh rate - This determines how flicker-free the image is. Anything less than 85Hz is likely to have some level of flicker. If your monitor is capable of displaying at 100Hz, then flicker won't be an issue. The minimum useable refresh rate is around 75Hz. But even 75Hz will be considerably more flickery than is good for your eyes. It's worth remembering that resolution and refresh rates are set by the graphics card, rather than the monitor. Check the specifications of your graphics card to find out what refresh rates and resolutions are available. Dot and stripe pitch - Dot pitch and stripe pitch are measurements that have baffled many people over the years. Different tube technologies and manufacturers have meant that measuring the gap between pixels has been done in various, often conflicting, ways. In previous years, to reduce confusion, we've avoided publishing these measurements. This year we've included them, because almost all the screens use an aperture-grille tube - with the exception of the Barco, which is an oddity in many ways. As aperture-grille stripe pitch is measured in the same way, we've decided to include those measurements. Inputs - The inputs on most models are VGA, the standard for CRT monitors. Unlike LCD monitors, CRTs are inherently analogue devices. That's why you have only digital connections on LCD screens. When using a monitor with more than one machine - perhaps there's a server by your desk - then dual inputs are ideal. Price - Another key judgement is, of course, how much you have to fork out. CRT monitor prices are fairly stable, mainly because they can't be made any cheaper. While smaller LCD displays are more affordable than CRTs, 20-inch LCDs remain twice the price of the average CRT. There's a broad range of prices for the models on test, even if you ignore the super-expensive Barco. If you can live without top-notch screen quality, then you'll save yourself a couple of hundred quid.