Sunday, July 17, 2005

Getting Your Color Right

thanks to pc mag for this tip :)

Printing photos has changed dramatically since the days when getting acceptable color took a great deal of knowledge or even more luck. Today, you can pick almost any printer, camera, and scanner at random and use them together without a problem. If you have a well-trained eye, you might quibble with the color, but most people are usually satisfied with it.

For those who aren't, the fixes run the gamut, from simple steps that anyone who prints photos should know about to complex tools of interest only to professionals and the most demanding photo enthusiasts. We'll focus on the simple fixes here and take a look at the advanced tools in the sidebar "Color Calibration Tools."

Why Color Needs Managing

Colors are harder to match than you might expect, for a number of reasons. A major challenge in printing from a computer is translating color information from one device to another. Two printers that use different cartridges almost always use significantly different colors for each primary: cyan, yellow, and magenta. If you define a color in terms of the inks in the printer—say, 20 percent cyan, 45 percent yellow, and 35 percent magenta—the color you get will depend on the printer you're using. This same problem applies to cameras, scanners, and monitors.

One way to deal with this is to create a color profile for each device and use a color management scheme to adjust colors based on the profiles. But individual profiles mean separate profiles for every possible variation, including every change in resolution or paper. Worse, to get the colors right, you'd need to adjust the profiles every time you changed ink cartridges, since the new ink could be from a different dye lot.

A simpler approach is to agree on a standard way to describe colors and let manufacturers worry about how to translate between the standard and each of their printers, scanners, and cameras. That way, you shouldn't have to worry about color management, or even be aware of it.

The agreement that serves that purpose is sRGB, which was originally defined to standardize typical monitors. The goal was to let people use any monitor, printer, scanner, or camera and get acceptable color across the board without having to create and manage profiles or otherwise think about color.

The scheme works well, despite some limitations. It's supported by nearly every printer, scanner, and camera that have come out since early 2001. And unless you tell Windows otherwise, Image Color Management (ICM) 2.0 in Microsoft Windows 98, 2000, Me, and XP assumes that every device is using sRGB. Thanks to sRGB, most people never need to learn much about color management. Still, to get the color you want, it helps to know the basics.

Paper Matters

Paper type
The most common reason for getting unacceptable color is printing on one kind of paper with the printer set for another kind. Many current printers have a paper sensor that's meant to prevent you from making this mistake. By default, the printer driver is set to detect the paper type and use the right color tables for that paper. In our experience, however, the paper sensor doesn't always pick the right paper type, particularly for printers that have settings for similar kinds of paper.

The best strategy is to set the paper type manually and use the automatic setting only as a fail-safe in case you forget. To do so, go to File | Print from the program you're working in, then click the Properties button. If, however, you're printing from the Windows XP Photo Printing wizard, click the Printing Preferences button on the appropriate wizard screen. Search through the options, changing them as appropriate. Any changes you make this way will apply only until you close the program you're printing from. To change the default setting for an option, open the driver by going to the Printers and Faxes dialog box, right-clicking on a printer name, and choosing Properties.

Some third-party photo papers come with recommended settings for popular printers; if yours does not, you'll need to experiment to see which paper setting gives you the best color. If you can't get acceptable color from any of the settings, switch to a different paper or consider exploring the professional-level tools that we discuss in the sidebar on page 76.

Let Your Driver Do the Work

Printer color management can take place in the printer driver, the application you're using, or the operating system. Unless you need the more sophisticated levels of color management, leave color to the driver.

In many cases you don't have to do anything; the printer is permanently set as an sRGB device. If you explore your printer's driver, however, you may find other options. If you're not happy with the color you're getting, make sure you haven't accidentally checked the wrong setting.

HP's current generation of drivers, for example, lets you choose among the default ColorSmart/sRGB (which is sRGB), Adobe RGB (of interest only if you have one of the few cameras that use this standard), and Managed by Application (the raw, device-dependent color; the setting to use if you want your application program to manage the color). If you want your driver to handle the color management, make sure it's set to sRGB.

Application-based color management is available in only a few programs, most notably Adobe Photoshop. Such programs typically take advantage of standard ICC (International Color Consortium, ) profiles, which are available on Web sites and come with some devices; you can also create them yourself with the appropriate hardware and software (see the sidebar). If you choose an application-based approach, the color management will work only for that application, so you'll still need the driver to manage colors for other programs.

If you use application-based color management and your printer driver has a special setting for this (as with the HP drivers), you'll have to change the driver setting every time you use the application. Otherwise, both the driver and application will try to correct for the same color shifts, and you'll wind up overcorrecting. In fact, if you get poor color only when printing from a particular program, check to see if the program has a color management feature. If so, you may have accidentally turned it on.

To check the setting in Photoshop 7.0, choose File | Print with Preview, and make sure the Show More Options box is checked. In the drop-down list just below the check box, choose Color Management. Unless you want Photoshop to manage color, make sure the setting in the Source Space box is Document and the setting for Profile in the Print Space box is Same As Source. (To use Photoshop's color management, you'd pick the appropriate profile to use instead.)

In the Windows world, color management at the operating-system level is widely ignored. HP, for example, says that none of its current drivers support it. But even HP recommends using the default Windows settings, since the feature could conceivably affect colors with some programs. To check the setting for a printer in Windows XP, choose Printers and Faxes on the Start menu, right-click on the printer, and choose Properties, then the Color Management tab. Depending on the printer, you may or may not see a list of profiles. If you do, ignore them, make sure color management is set to Automatic, and click OK.

The Best Printing Path

Many, if not most, ink jet printers today can print either from a computer or directly from a camera or memory card. But memory limitations in the printer often restrict color-rendering algorithms to less sophisticated versions of the ones in the printer driver. If you're not satisfied with the color from direct printing, try moving the files to your computer and printing from it.

The color should be better. If it's not, look for differences in settings between the printer's built-in menus and the printer driver. For example, the default paper-type setting for direct printing is often glossy paper, since the assumption is that you're printing a photo, while the default setting in the driver is usually plain paper.

There's one important exception to the rule that printing from the computer gives better color than printing directly. If you're making copies on an AIO, giving the copy command from the front panel will often result in a closer color match to the original than giving the command from a control program on the computer.

Specifics vary from one AIO to the next, but in general, if you give the scan command from the AIO's front panel, the color information will go directly from the scanner to the printer, with no intermediate stops. The two are usually fine-tuned for each other, and there's only one translation step, from what's called the color space for the scanner to the color space for the printer, so you should end up with a close match.

If you give the Copy command from your computer, one of three things may happen. With some AIOs, the command simply tells the AIO to copy, just as if you had given the command from the front panel. With others, it sends the scan to the computer to take advantage of the superior algorithms in the driver, but stays with only one translation step, so the color may improve.

With still other AIOs, however, the scan goes to the computer, where the driver first translates the colors to the monitor's color space, then from the monitor's color space to the printer's color space before printing. Much like in the game of telephone, some data gets lost at each step, so the final colors will not be as close a match as with the other two approaches. The best way to avoid this problem is always to give the copy command from the front panel of your AIO.

Nearly Effortless

Thanks to sRGB, color management today is a classic example of the 80/20 rule—the idea that you can get most things 80 percent right with 20 percent of the effort it takes to get them 100 percent right—except in this case the split is closer to 90/10. If you want to go further, check out "Color Calibration Tools." But rest assured that with the information we've covered and a capable printer, you already know enough to print photos that will easily stand up to what you'll get with film dropped off at your local drugstore.

Color Calibration Tools

If you want something closer to perfection in your photos than what you get from sRGB, plenty of tools can help.

You might want to try basic monitor calibration, which consists largely of making sure your brightness and contrast controls are adjusted properly. A good place to start is at, where you can download the free DisplayMate demo program to use as a calibration tool.

If you want to move to the next level, we highly recommend the full version of DisplayMate, which is what we use at PC Magazine Labs both to calibrate monitors and to test them. You'll also find a wealth of useful information on the DisplayMate site, including instructions for how to use DisplayMate to calibrate your printer.

For still more sophisticated calibration, you need a package that creates ICC profiles based on measurements taken with a colorimeter (which measures colors in a manner similar to the way the human eye sees them). You can then use the profiles with the color management features in programs like Photoshop.

ColorVision ( ) offers a range of excellent choices targeted at various types of user, from the digital photography enthusiast to the professional, and covering both monitors and printers. PC Magazine has looked at several of these packages, and we've generally liked them. ColorVision ColorPlus, a monitor calibration product ( ) has a street price of $99. The ColorVision PrintFIX Suite goes for $399. Our review of the previous version can be found at http;// .

These products are part of the Pantone ColorVision product family, the result of a marketing alliance between ColorVision and Pantone ( ). The current versions are built around a new, and presumably improved, colorimeter. Be advised, though, that these tools are best suited for professionals and perfectionists, as they require a lot of extra work for relatively little payoff.

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