You may have seen them in sci-fi tv shows– slender flat-panel monitors with that oh-so-twenty-first-century look.
But you may not have realized that those LCDs (liquid crystal displays) connected to computers whose digital image signals still had to undergo a complicated conversion, to analog and then back to digital, in pretty much the same way as your old cathode-ray tube (CRT).
Welcome to the next generation.
In the same way that digitally recorded, digitally mixed music outputted onto a digital format sounds crisper than a digitized analog recording, digital LCDs promise better performance than their analog counterparts because they keep your Mac’s digital image signal digital.
Macworld Lab tested six digital LCDs to see if the digital promise holds true–the $3,999 22-inch Apple Cinema Display, the $1,299 15-inch Apple Studio Display 15.1 LCD, the $1,199 15-inch HP Pavilion FX70, the $1,299 15-inch NEC Technologies MultiSync LCD 1525X, the $1,000 15-inch Philips Electronics Brilliance 150P, and the $3,095 18-inch Princeton Graphics DPP800. A jury of experts looked at the monitors’ sharpness, color fidelity, viewing angle (how far you can move from directly in front of the screen and still see its contents clearly), and quality of DVD-video playback. (See the table, “Digital Divas: 6 Digital Flat Panels Show Off”).
Although LCDs are more expensive than same-size CRTs, they do offer advantages beyond taking up less space on your desk (see “The World Is Flat,” December 1998). Unlike the CRTs you’re used to, LCDs have a backlight that is always on. Because of this, and because LCD pixels hold their color longer, you get much less flicker–and will likely experience less eyestrain. This makes LCDs ideal for viewing text, and they won’t display weird effects such as moiré patterns in your images. Compared with CRTs, LCDs also use 90 percent less energy and run with less heat.
Through the Looking Glass
But LCDs bring some trade-offs. They have a more limited viewing angle than CRTs–if you stand up and look down at your LCD, you’re likely to see a dark, posterized version of your image.
Color accuracy also suffers with LCDs, making them inappropriate for graphics professionals who need consistent, reliable color. Although typical LCDs can display thousands of colors–plenty for most purposes–the monitors simply can’t reproduce as many colors as a CRT. And as you look at an LCD from different angles, you’ll notice subtle color shifts–and when viewed from more extreme angles, colors shift wildly.
LCDs are also subject to dead pixels, which show up as miscolored dots on your screen. Although none of the monitors we tested had this problem, it does occur; most manufacturers consider no more than about four acceptable.
Let’s Get Digital
When you look at a JPEG of your sister’s new baby on your monitor, your computer is sending your monitor data about how to display that image. Analog and digital LCDs differ in the way they process that signal.
Analog LCDs take the digital signal from your computer, convert it to an analog signal in your graphics card, and then convert it back to a digital signal in the monitor. There are several basic problems with this method. This conversion process is a tricky business; if the data is even slightly out of sync, your image may end up misaligned–blurry or marred by visual artifacts.
And since LCDs support only one resolution natively–they yield their best results when the number of pixels displayed is the same as the number of pixels physically present on the panel–an analog LCD has to translate any other frequencies and resolutions, increasing the chance for error.
Analog signals also carry more noise, which can muddy your images much like static on a telephone line distorts sound.
Digital LCDs are more direct–they simply pass along a computer’s digital signal. This requires fewer components, which should also make digital LCDs cheaper to produce, although you won’t see lower prices until demand increases.
Digital Video Card Required
Although digital LCDs are technically simpler, they do require a special video card to support the digital interface. Some of the LCDs we tested, however–the NEC, HP, and Philips models–offered both digital and analog interfaces. You’ll find this particularly useful if you plan to update to a digital video card and don’t want to buy a new monitor when you make the switch.
The Great Debate
Despite the benefits digital LCDs have over analog ones, some companies have been slow to make the switch. One reason is the continuing debate over digital interface standards–DVI (Digital Visual Interface) versus DFP (Digital Flat Panel), a subset of DVI technology. These different standards affect what kind of video card you’ll need to run your monitor–none of the monitors we tested includes a digital video card.
With the addition of a DFP-to-DVI converter, the $99 ATI Xclaim 3D Plus (905/882-2600, www.ati.com) supports all the 15-inch monitors we tested. For the Apple Cinema Display or Princeton Graphics DPP800, you’ll need the ATI Rage Pro 128 card with digital and analog outputs and a G4 with an AGP graphics slot. If your G4 didn’t come with this card (all new G4s do), you can buy it for $99 from the Apple Store (800/ 692-7753, www .apple .com). If your AGP graphics card has just one output, you’ve got analog only.
Other cards from Formac Electronic (925/ 251-0100, www .formac .com) and ProMax Systems (800/ 977-6629, www .promax .com) should be available to support these larger panels by the time you read this. (For an explanation of the different technologies, see the online sidebar “Facing the Interface” at www .macworld .com/ 2000/ 07/ features/.)
The Proof Is in the Pixels
The LCDs we tested fell into two groups–15-inch and larger panels–and we picked an Editors’ Choice in each category. We tested all the displays at maximum brightness and native resolution settings, using the $1,499 21-inch CRT Apple Studio Display as a reference (see “Think Big,” June 1999).
The first step in setting up and using a flat panel is adjusting color and brightness. Although it is possible to adjust both through the Monitors control panel in the Mac OS, you might find it more convenient to use the controls right on your monitor.
All the panels include controls for adjusting brightness. The HP adds several presets for color temperature (which changes the overall tone of your image), sharpening, and gamma–a type of contrast adjustment. The Philips has picture alignment controls, useful primarily for analog mode. The NEC offers the most precise control, including brightness and contrast adjustment, plus sliders to control levels of red, green, and blue.
Adjustment controls aside, the most important aspect of any flat panel’s performance is how well it displays images, and these monitors all performed admirably (for details, see the benchmark “Flat Panels Go Digital”). All the monitors offered excellent sharpness. In particular, the Apple Cinema Display’s image was sharper than that of our reference CRT, the Apple Studio Display, at all resolutions–showing greater detail in one test image. And all the LCDs displayed much sharper and crisper text than our reference monitor.
Most of the panels also impressed us with their broad viewing angles–we could see the images clearly from a wide angle and only somewhat less clearly from vertical angles. The Princeton fell a bit behind the pack, with narrower viewing angles. Also, the NEC had image problems–even when we looked at it head on, it darkened the top and bottom areas of images.
The characteristic that most differentiated these models was their ability to reproduce color accurately and consistently at different angles. The Apple Cinema Display produced excellent color, although it tended to shift to a blue tone as we moved horizontally or vertically. The HP, NEC, and Philips models also impressed us with their accurate, saturated colors but had a similar color-shifting pattern.
The flat Apple Studio Display produced generally fine color, but we found that the best viewing angle came when we moved slightly off center horizontally. In some light areas of the image, we saw a posterizing effect from wider angles.
The Princeton fared worse in color fidelity. Its images seemed washed out compared with our reference CRT’s, and it displayed an overall bluish tint even after we adjusted its color temperature.
If you plan to replace your CRT monitor with an LCD, you’ll probably want the new display to perform all the same functions. This becomes a problem where DVD-Video is concerned. If you have the Rage 128 Pro for your G4, you can simply plug the monitor right in. But if you use the $99 ATI Xclaim card–your only option if your Mac doesn’t have an AGP graphics slot–you can’t decode and watch DVD movies.
To determine video quality, we tested DVD playback using the G4’s built-in Rage 128 Pro card and found acceptable performance on all the monitors. The HP, flat Apple Studio Display, and Philips offered exceptionally sharp images and good color range. The Apple Cinema Display seemed darker and less crisp than the others, perhaps because the smaller screens packed the images into a smaller space, making them appear sharper.
Other features distinguished the monitors. The NEC and Princeton monitors both have four USB ports that turn your panel into a USB hub, and the NEC also has two upstream USB ports, allowing you to connect two computers to a single panel. The Apple models sport two USB ports each, and the Philips has a bay for an optional hub–only the HP has no USB potential. Also, the HP and Philips models both have built-in speakers, and the Philips even includes a microphone built into the panel itself.
Macworld’s Buying Advice
Despite the advances in LCD technology and the innate superiority of digital LCDs, these monitors still aren’t appropriate for demanding graphics professionals–their color shifts make it difficult to display images accurately.
But these monitors are certainly great if your primary concern is more desk space, lack of flicker, a second monitor–or simply great style. And if you’re already considering an LCD, by all means go digital.
The HP Pavilion FX70 is our 15-inch-monitor pick. It displays saturated colors with excellent depth, and its images remain crisp even during DVD-Video playback.
The Apple Cinema Display is the clear winner of the two larger-size panels we looked at. Even at almost $4,000, its impressive image size, excellent color and sharpness, and gorgeous case make it a worthwhile choice. Remember, however, that when we went to print it only worked with G4s that had an AGP graphics slot.
The bottom line is that you may find a digital LCD a welcome addition to your computer system if you appreciate sharp text, need to conserve desk space, and don’t need precise color–and if you’ve got a few thousand dollars burning a hole in your pocket.
BEST LARGE DIGITAL FLAT PANEL
Apple Cinema Display
Sharp and bright with excellent color and great design; requires graphics card compatible only with G4.
Apple Computer (800/ 692-7753,