What Is Monitor Calibration

Your monitor needs to be calibrated so that it accurately displays the colors contained in any given image. You calibrate your monitor by adjusting a number of different variables, which may include the following, depending on your monitor and the tools you use to calibrate:

The balance of colors on your monitor: This balance corrects any color tints or colorcasts.

Brightness: The brightness control historically adjusts the black point, which is the darkest point on the monitor.

1 Contrast: Adjusting contrast used to mean adjusting the white point, which is the lightest point on the monitor. As you calibrate your monitor, you need to experiment with different monitor white-point settings until the white of the monitor looks as pure as possible.

i Gamma: Gamma is the brightness of mid-level tones in an image.

In technical terms, Gamma is a parameter that describes the shape of the transfer function for one or more stages in an imaging pipeline.

i White balance: You adjust the white balance setting to try to get the brightness as close to natural daylight as you can.

You have a few choices for what tool you can use to adjust your monitor brightness:

^ Expensive calibration equipment that can cost $3,000 or more

^ A low-cost hardware device priced at less than $300

^ Software tools provided by Adobe (or your OS developer) to set up your monitor

We discuss how you use low-cost hardware devices and software tools in the sections "Calibrating with Hardware Devices" and "Adjusting Hardware Controls on an LCD Display," later in this chapter.

Working with CRT versus LCD Monitors

Computer monitors come in two flavors — CRT (cathode ray tube) and LCD (liquid crystal display). The CRT monitors look much like old TV sets, and the LCDs offer a sleeker, thinner look. Each type has its pros and cons when it comes to monitor calibration.

LCD monitors, although now more prolific and newer in the marketplace, just don't match the color clarity you find in CRT monitors. In addition to improved color clarity, CRT monitors also cost much less than LCDs. As of this writing, a Dell Trinitron 21-inch display sells for less than $200 at online reseller outlets — try www.tigerdirect.com. CRTs have their downside, however. In addition to their large size, overall bulkiness, increased power consumption, and the excess heat they produce, they're becoming increasingly scarce. Many CRT manufacturers have discontinued entire lines of CRTs in favor of the newer LCD technology.

If you find a good value on a CRT monitor, find out when the monitor was made. If you purchase an older, used monitor, it may have exceeded its useful life. You can expect to get about three to five good years out of a CRT before it starts losing definition and color clarity. We can't give you a magic

(d formula, however, because monitors vary greatly in fidelity and life expectancy. You can easily check the date a monitor was manufactured by looking at the label affixed to the back of the monitor.

Because of the popularity of LCD monitors and the anomalies associated with calibrating LCD displays, we thought we'd point out some real problems you may encounter when trying to calibrate an LCD display with the visual (software) calibration utilities for both Windows and the Mac.

The visual calibrators were designed with CRT displays in mind. LCDs differ from CRTs in two fundamental ways:

1 LCDs are much brighter than CRTs and have a much higher overall contrast. Setting picture contrast to the highest setting on an LCD, as instructed by the calibration utility, usually makes the picture far too bright for the calibration utility to work properly.

1 The LCD monitor controls work differently than CRT controls. CRT

brightness and contrast controls are part of the monitor hardware, just like a CRT television set. The brightness control adjusts the black point, and the contrast control adjusts the white point by varying the output of the electron guns. The same is true of the color adjustments.

An LCD (unless it's a very expensive professional model) varies the brightness and contrast by changing the internal monitor color Look Up Tables (LUT) to change the monitor image. The backlight is always bright — very different from a CRT.

We worked long and hard to create a foolproof way to visually calibrate an LCD monitor. If you decide to use a visual calibration tool, check out the section "Adjusting Hardware Controls on an LCD Display," later in this chapter, and you should get a result that matches your print outputs much more closely than the monitor default settings. Just keep in mind that you need to use a hardware calibration device for the very best results.

An LCD monitor that's calibrated for print work always looks darker and warmer in tone than with the factory default settings.

If you have an LCD monitor now, keep your eye on product reviews and current literature. The LCD technology is new and continually advancing. Computer CRT monitors have been around for more than 25 years, with 25 years of continued research, development, and improvement. As time goes on, we expect LCD monitors to advance and ultimately render even better color clarity than the best CRTs of years past.

Calibrating with Hardware Devices

We skip the high-end costly devices and suggest that, at the very least, you should make one valuable purchase for creating a monitor profile — a hardware profiling system. (See Chapter 4 for more on monitor profiling.)

On the low end, you have some very affordable devices that go a long way in helping you adjust your monitor brightness and color balance:

¡^ ColorVision Spyder2express: This calibration system is one of the newer devices on the market. For as low as $69, you can purchase an easy-to-use, three-step device that balances the color on your monitor and adjusts it for optimum brightness (for both Macs and PCs). This device is receiving five-star ratings at online resellers, including www.amazon.com.

¡^ Pantone Huey Monitor Color Correction system: This new, low-cost calibration system can calibrate both CRTs and LCDs (and supports both Macs and Windows). This unit retails for $88 and sells for $74.95 at Amazon.com, as of this writing.

¡^ GretagMacbeth Eye-One Display 2: For a little more money, you can order this low-end calibration device with superb capabilities from GretagMacbeth (www.gretagmacbeth.com) — a company that has long been a leader in sophisticated hardware equipment for creating calibrations and color profiles. This device costs $249, as of this writing.

Eye-One Display 2 is an easy-to-use profiling tool that works with CRT displays, LCDs, and laptop computers. You attach the suction cup that comes with your Eye-One Display 2 to your monitor (see Figure 3-1), click a few buttons in the software application accompanying the hardware, and Eye-One Display 2 eventually prompts you to save a monitor profile. Your operating system automatically uses the profile you create when you start up your computer. When the profile kicks in, your monitor is balanced, using the settings determined when the device performed the calibration.

If you decide to purchase the Pantone Huey or the ColorVision Spyder2express, either device will give you the best possible result on an LCD monitor if you do a rough visual calibration for monitor brightness and contrast before using it. Look over our tips for visually calibrating an LCD monitor for brightness and contrast with the built-in monitor controls (see the section "Calibrating LCD monitors that have brightness and contrast controls," later in this chapter) and at least get your LCD monitor in the ballpark first.

Figure 3-1: The Eye-One Display 2 calibration device helps you create a monitor profile.
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