Monitors and Video Cards
Liquid crystal display (LCD) monitors have essentially replaced bulky cathode ray tube (CRT) monitors in most studios. When you shop for a monitor for Photoshop use, the primary criterion is whether the monitor accurately reproduces a wide range of color after calibration. Unfortunately, reading technical specifications such as contrast ratio and maximum brightness won't help you. Contrast ratios are not standardized among manufacturers and often don't take calibration into account. Maximum brightness is meaningless for photo editing, because what really interests you is whether the monitor can give you a good black level so that you can judge shadow detail. To do this, a monitor must reach the optimal brightness range for calibration, typically between 100 and 120 candelas per square meter (cd/m2). But because monitor companies like to brag about brightness, some inexpensive LCD monitors can't be turned down that far!
Because much of the information available about monitors is unreliable or irrelevant to Photoshop work (mostly written from the point of view of office work or gaming), the best way to shop for a Photoshop monitor is to get recommendations from photographers, prepress professionals, and online professional photography forums you trust.
For pure two-dimensional (2D) image editing, you probably won't benefit from spending more money on the kind of high-end three-dimensional (3D) video card that makes gamers happy. The bottleneck in redrawing Photoshop images is almost never the video system—it's getting the image data out of RAM (or even worse, from disk) to the video system. The one video card spec that affects 2D Photoshop performance the most is video RAM. Aim for a video card with lots of video RAM onboard—at least 256MB, and preferably 512MB. If you're running multiple large monitors, try starting at 512MB.
Photoshop CS4 is the first version of Photoshop that can take advantage of a video card's graphics processing unit (GPU) for some display operations (not image-processing operations, though). If your video card supports OpenGL, you may see new, smoother panning and zooming options in Photoshop CS4, such as free rotation of the canvas.
The 3D capabilities of a video card used to be irrelevant to Photoshop, but since the addition of 3D and video editing in Photoshop CS3 Extended, 3D graphics hardware now comes into play. But you may not have to upgrade your video card. If you have a 3D video card that's sufficient to run general CAD programs, it's good enough for Photoshop Extended.
Monitor Calibration and Profiling
If you want to be reasonably confident in what you see onscreen, some kind of monitor calibration and profiling is essential. The free, eyeball-based, software-only monitor calibrators, such as the Apple Display Calibrator Assistant, are better than nothing. Unless you work in a cave, however, you'll find it's extremely difficult to get consistent results with such programs, because your eyes—and hence your "monitor calibration"—adapt to changing lighting conditions.
We believe that every serious Photoshop user would be better served by using a hardware color-calibration puck to measure the behavior of the monitor, along with its accompanying software, which will set the monitor to a known condition and write a monitor profile. Several good, relatively inexpensive hardware-based monitor calibration packages are available. We like the Eye-One Display from GretagMacbeth, Color Solutions' basICColor Display, or the Datacolor Spyder. All of these systems can calibrate both CRT and LCD monitors, and any of them will do a better job of keeping your displays accurately profiled than any of the eyeball-based tools.
While manufacture of high-end CRTs has essentially ceased, they still have their diehard fans. If you're trying to eke out another year of use from your beloved CRT, keep an eye on its brightness level when you recalibrate it. When a CRT's brightness level drops below 95 cd/m2 after you set the black level, it's time to start budgeting for a new LCD monitor.
Any Mac that supports multiple monitors can apply the specific color profile for each display properly, and therefore you should generate a separate profile for each display that you want to use for critical color evaluation. However, some Windows video cards that support multiple monitors report themselves to the operating system as a single device with which only one display profile can be associated. When buying a video card to use with Photoshop in Windows, it's best to assume nothing and do plenty of research.
We don't have much experience with multiple-monitor Windows setups, but we do know that, aside from the profiling issue, they're nearly as easy to set up in Windows as on the Mac. If your Windows video card doesn't support separate profiles for each monitor connected to it, you can at least display the Photoshop document window on your best profiled monitor and arrange your Photoshop panels on another monitor.
Displays on notebook computers lag behind desktop monitors in quality, because notebook displays need to be thin, light, and low-power. If your only Photoshop computer is a notebook, consider connecting a good external monitor when you're at your desk. An external monitor port is built into many notebooks, and you'll love the extra work area. If you must use the notebook's built-in display to evaluate color—for example, on a photo shoot in the field—it's critical that you create a monitor profile for it using a hardware calibrator. That technique still won't make a notebook display as good as a desktop monitor, but at least it will be as accurate as it's ever going to be.
Some newer LED-backlit LCD notebook monitors, such as the display on the Apple MacBook Pro, are capable of a wider color gamut than the older, more common LCD notebook monitors that use fluorescent backlights. However, as we write this, even a calibrated LED-backlit notebook monitor can't match the performance of a calibrated high-quality desktop monitor.