Quick Guide to Color Management

As we all know, it can be hard to match what comes out of your printer to what you see on your computer screen, much less what you saw in your camera's viewfinder. Yet it can be done if you follow the principles of color management, one of the most important--and confusing--topics in digital imaging. This quick guide to color management cuts through the terminology, helping you set up Adobe Photoshop for great color in fifteen minutes. The guide focuses on Adobe Photoshop 7.0 for Windows XP, but the principles are just the same whether you're using 7.0, Elements, or CS, on PC or Mac.

Terminology

Before getting started, there are a couple of terms you may want to know. If you're in a hurry, feel free to skip this section; you can always come back to it later if you have questions.

• Color management is about making sure that what comes out of your printer looks like what you see on your computer screen, which in turn looks like what you saw in your camera's viewfinder. Color management software called ICM, for Image Color Management, comes with Windows; a similar package called ColorSync is installed on Macs.
• Color models are ways of describing color digitally. The most widely used color model is RGB, for red-green-blue, which defines all colors in terms of how much red, green, and blue they contain. For example, black has no red, green, or blue, and is represented by R=0, G=0, and B=0; white has the maximum amount of all three colors, and is represented by R=255, G=255, and B=255.
• Color spaces translate the arbitrary numbers of a color model into absolute terms--how much ink, for example, to lay down for the color black--and define the total range of colors that a given image file or device (such as a monitor or printer) can display.
• Color profiles are small files that tell ICM what color space to use for each image and each device.

1. Choose your working color space in Adobe Photoshop.

Your working color space is the space that all of your images will be stored in. When you look at an image on screen or print it out, ICM (or ColorSync, if you have a Mac) will convert each pixel from your working color space to your monitor's or printer's color space. That way, the print will look like the image you see on screen.

To choose your working color space, go to Edit > Color Settings to display the Color Settings dialog box. Under Working Spaces, set RGB to:

• sRGB IEC61966-2.1 is the standard color space on the web and is close to the range of colors that mid-range digital cameras can capture and computer monitors can display. sRGB is the best choice if: (1) your digital camera outputs only sRGB JPEG files, or (2) you will only be displaying your photographs on the web, e-mailing them to friends and relatives, etc.
• Adobe RGB (1998) can display a wider range of colors than sRGB, closer to what high-end digital cameras and film can capture and inkjet printers can print. Choose Adobe RGB (1998) if: (1) your digital camera can output RAW or TIFF files, and (2) you will be making prints of your photographs.

Under Color Management Polices, make sure that RGB is set to "Convert to working RGB" and all three of the check boxes at the bottom are checked to indicate "Ask when opening" or "Ask when pasting." Then click OK. (Don't worry about the CMYK, gray, and spot settings; these only matter if you are working in black and white or preparing images for publication.)

Note for users of Photoshop Elements 3.0: Elements simplifies the process of choosing your working color space. Go to Edit > Color Settings (or File > Color Settings if you are using a Mac), and choose one of the following three options:

• No color management, the default setting, is not recommended, as it will make it very difficult for you to match your prints to what you see on the screen.
• Limited color management assigns the sRGB profile to all images. This is the equivalent of choosing sRGB above, and is a sensible choice if your digital camera outputs to sRGB files or you will only be processing images for use on the web.
• Full color management uses Adobe RGB (1998) for print images and sRGB for web images. This is the equivalent of choosing sRGB above, and works well if you do a lot of printing.

2. Profile your monitor using Adobe Gamma.

Adobe Gamma is a control panel that helps you create a color profile for your monitor so that ICM can display colors accurately. Adobe Gamma comes with Photoshop and Photoshop Elements. To make sure that it is installed on your computer, go to Start > Settings > Control Panels; if you don't see it listed there, you can use the installer on your Photoshop CD to install it.

Before running Adobe Gamma, make sure that your monitor has been on for at least half an hour, and darken the room (turn the lights off and draw the shades). You may also want to have your monitor's manual handy, though you shouldn't worry too much if you can't find it. Note also that you should run Adobe Gamma monthly, as every monitor's colors change as the hardware ages.

When you are ready, go to Start > Settings > Control Panels > Adobe Gamma to open the Adobe Gamma control panel. Select the wizard, press Next, and Adobe Gamma will walk you through the six-step profiling process:

1. Name profile: Choose a name you'll remember, as you will need to find the profile again when configuring your scanner software.
2. Brightness and contrast: Flat-screen LCD monitors have no contrast control. This is okay; use the brightness control by itself.
3. Monitor phosphors: If you don't know what these are (and can't find them in your monitor's manual), choose P22-EMU.
4. Gamma: Uncheck "View single gamma only," and adjust the red, green, and blue sliders individually. Set the desired gamma to 2.20 for Windows, 1.80 for Mac.
5. Hardware white point: Click Measure to estimate your monitor's white point, or enter: 6500°K if you have a flat-screen LCD monitor, or 9300°K if you have a CRT monitor (one with a TV tube).
6. Adjusted white point: Select 6500°K.

Your monitor is now profiled to display color accurately.

Note for Macintosh users: Macintosh has its own monitor calibration control panel similar to Adobe Gamma; in OS X, it is accessed by going to Control Panels > Display > Calibrate.

Note for advanced users: A more accurate method of calibrating your monitor in color-critical situations is to use a spyder, a small device that mounts on your screen and measures the colors that it is outputting rather than asking you to eyeball them.

3. Importing images from a digital camera, scanner, or file.

The procedure you use when importing images varies depending on whether the picture is coming from a digital camera, a scanner, or a file. But the goal remains the same no matter what the source is: to make sure that your computer knows what color space the image was created in, so that it can translate it accurately into your working color space.

4. Outputting images for web or print use.

Outputting an image for web use, or printing it on an inkjet printer, involves converting it from your working color space to the appropriate output color space. This section will help you choose the best settings for great-looking prints or online pictures.

That's all there is to it!