Calibrate a Monitor With a Colorimeter
Calibration Improves the Match Between Monitor and Print Colors
Jan 4, 2009
Once calibrated, a monitor presents "true colors "to the viewer. As a result, the prints made from the edited images will closely match the colors the viewer sees onscreen.
While a monitor can be calibrated manually at litle or no cost, the easiest and most accurate way is to use a colorimeter, a device for measuring the accuracy of the monitor's colors. Since some of these devices look somewhat like a spider, that is what they are sometimes called. A calibration system that uses a colorimeter automatically brings the color output of the monitor in line with standards set by the International Color Consortium (ICC),
What a Colorimeter Does
The colorimeter software tests the monitor's settings by presenting various colors, grays, whites, midtones and brightnesses for the device's sensor to evaluate, explain Sally Werner Grotta and Daniel Grotta in their book PC Magazine Digital SLR Photography Solutions (2006). The colorimeter evaluates how those optimum colors are displayed at the monitor's current settings and sends that information to the computer, the Grottas explain. Next, the colorimeter software compares how well the display of the optimum colors it sent to the monitor compare to the monitor's unadjusted display. Adjustments are then made and a color "profile" is stored in the computer.
To calibrate a monitor, follow the instructions that come with the colorimeter. Most manufacturers will advise some preliminary steps, including:
- Turning off the screen saver and energy saver modes.
- Letting the monitor warm up for the time specifed by the colorimeter manufacturer because the colors displayed on a monitor change as it warms up.
- Disabling another manufacturer's monitor calibration system. For example, Adobe Gamma is the calibration system installed with the Adobe Photoshop photo-editing program. The Adobe website gives instructions for disabling it . To find out if your monitor has ever been profiled, right click the desktop, then choose Properties, then Settings, then Advanced, then Color Management. Remove any listed profiles. Restart the computer.
- Setting the color depth of the display to at least 16 million colors (24-bit color)
Screen Types
After the monitor is warmed up and the software installed, place the colorimeter on the computer screen--either the big, bulky CRT (cathod ray tube) one or the thin, flat LCD (liquid crystal display) one. Suction cups are supplied for attaching the spider to the CRT screen. Do not use suction cups on the LCD screen, as they might damage it. Instead, the colorimeter manufacturer supplies a counterweight for you to use..
A monitor should be calibrated weekly if you use it a lot. If you use your monitor seldom for print work, monthly calibration should be enough.A printer used for photo work should be calibrated too. The tools, however, are different from those used to calibrate a monitor. And even if you do not print your own photos, after editing your images on a calibrated monitor, you can take your picture CD or DVD to a good photo lab to get prints you will be pleased with.
Other Equipment That Can Be Calibrated and Buyer's Guides
Scanners can be calibrated too. And since the type of screen that reflects the projector's light really affects the image viewers see, digital projectors should be calibrated too. Read PCPhoto's article "Toolbox: Display Calibration" and consult the magazine's buyer's guides to determine which calibration system is best for you.
Sources:
Jaynes, Joseph T. and Rip Noel. Spring Into Digital Photography. Upper Saddle River, NJ: Addison-Wesley. 2006.
