Digital Directions: True Colors

Printing your own photos is one of the most rewarding aspects of being a photographer, exceeded only by taking a really great picture. And getting good prints from an inkjet printer isn't as tough as it used to be. With affordable calibration tools and programs from outfits such as ColorVision and X-Rite, it's easy to match what you see on your computer monitor with what your printer produces.

But making great prints? Large, gallery-quality prints? For that, you must go further, and get into the color-space settings for your imaging software, printer, camera, and scanner.

There are two types of color space: working and device. The first represents the range of colors that can be used to translate the digital data captured by a camera or scanner. It also regulates the way those colors are translated back into data used by a computer monitor or printer to produce color. Most computer color-management systems (ICM 2.0 on the PC and ColorSync on the Mac) are set to translate colors using the default sRGB working space, which approximates all of the colors in a typical PC monitor. The larger Adobe RGB 1998 working space, on the other hand, was designed to encompass most of the colors achievable by CMYK inkjet printers. (This isn't to be confused with a standard SWOP CMYK color space, which is smaller than either of the others and describes the colors achievable in most CMYK printing presses.)

Ideally, a working color space should be larger than a device's color space (more accurately described as its color gamut). That way, all of the colors recorded by, say, a camera can be translated into colors within the working space. Otherwise, it's like making an intricate drawing of a scene that has 500 colors with only 400, 200, or 100 colored crayons. And that is analogous to converting the colors captured by a decent digital SLR into Adobe RGB, sRGB, and the SWOP CMYK color space. (Unfortunately, the last regulates image color in this magazine, which is why our picture descriptions don't always match what you see on the page.)

The right choice
Most digital SLRs, high-end EVFs, and even a few compact digitals let you set your camera's color space to either sRGB or Adobe RGB 1998. (If your camera doesn't have this option, it probably defaults to sRGB.)

The difference between these two choices is shown for the Canon EOS-1Ds SLR in the print comparison below. Using the sRGB color space setting (#5 in the EOS-1Ds) results in slightly less color saturation in bold flower colors and reduced red in the skin tones compared with the same image captured and printed using the larger Adobe RGB 1998 color space. But working color spaces and color gamuts are really 3-D entities, and can be visualized by creating a 3-D CIEL*a*b* diagram with a variety of software programs, such as Chromix's $149 ColorThink 2.1. (This cool 3-D chart program for PCs and Macs is also a powerful profile management and repair tool.) In the diagrams shown here, points along the a* and b* axes describe color hue and saturation (–a to +a values represent bold green to bold red, –b to +b values on the next axis represent bold blue to bold yellow), while the L* axis, located in the neutral crossing point of the a* and b* axes, describes the brightness level (black to white, on a scale of 0–100).