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Color printing primer

What you see is not always what you get. Multimedia hed: Color printing primer dek: what you see is not always what you get. dek: it takes work to make output match what you see on the screen.

The revolution in color inkjet printing technology forever changed the deskscape. For less than $100, printers from companies such as Canon, Epson, H-P, Lexmark, and others help users produce photo-quality output. But there is a price to be paid for this capability. As color printers became better and better (and cheaper), users began to demand more from them-not just higher resolution but better, more accurate color. This quest engendered an endless cycle of continued printer improvements to find color nirvana: true WYSIWYG color.

Before starting on the path to accurate color, there are many roadblocks that must be overcome, including price. Somewhere along the way, you are going to have to stop and ask yourself, “How much am I willing to pay for really accurate color?” Your answer determines which of the several available solutions are appropriate for your particular situation. Our goal is to point you toward affordable solutions to the color-output problem.

Real-world color

There are few problems standing in the way of obtaining a truly accurate color match between what you see on the monitor and what your printer delivers. The most fundamental difference is that when looking at a monitor, you are viewing an image by transmitted light. As when you view a slide on a light box, light is coming from behind the image. When looking at printed output, your eyes see the reflected light off of the print. Right away there are differences, and these differences can be exacerbated by environmental factors, including monitor glare, video quality, and ambient-light color. While light may appear white to our eyes, it actually comes in many hues depending on the light source. (For more information on this phenomenon, check out the H-2 Cinematographers Field Guide www.kodak.com/US/en/motion/
support/h2/index_txt.shtml for a look at the true colors of common light sources.

Depending on the chemical composition of the inks used, the output of some inkjet printers exhibit a characteristic called metamerism. Metamerism refers to situations in which output from a color printer looks fine under one set of viewing conditions but not under another. When this occurs, the match is said to be conditional. There also can be geometrical and observer metamerism. What all this mumbo jumbo boils down to is that sometimes colors look one way under certain lighting conditions and another way in others.

Because metamerism can never be completely eliminated with output from some desktop printers, you should make sure it’s viewed under consistent lighting. If you go into any professional photographic lab or commercial printer, you’ll find a special area for viewing output. This area will have test prints posted and will have lighting fully corrected for daylight. If it looks good there, it’ll look good anywhere. Most computer users can’t afford the kind of viewing boxes professional labs have, but Ott-Lite www.ott-lite.com sells affordable accessory lamps that can bring color-correct viewing to your desktop printer. Ott-Lite offers a family of modestly priced VisonSaver lights that you can place near your printer to help you see color properly. Ott-Lite’s 13-watt portable lamp should fit into anybody’s work space, and is blueberry-colored to match a Macintosh digital darkroom. A similar model in a neutral graphite color sells for $69.95. Need one you can clamp to a table and angle out over your printer? Take a look at the 18-watt Clamp-On Lamp for $129.95.

Calibration options

Once you’re aware of the effect of environment on output, you need to take steps to bring your computer system into color harmony. There are a few ways to minimize problems, but the key is knowing what the color of your image is to begin with. Using Adobe’s Gamma software, www.adobe.com which is automatically installed with recent versions of Photoshop and even the inexpensive Photoshop Elements, is the first step. The Gamma control panel lets you calibrate your monitor’s contrast and brightness, gamma (midtones), color balance, and white point. There are two ways to work with Gamma and both are easy, including a step-by-step wizard approach. More detailed information of setting Gamma can be found in Adobe’s online Technical guides www.adobe.com/support/
techguides/color/gamma/gammastepbystep.html. The settings you obtain by working with the Gamma control panel are used to create a profile for your monitor that color management systems can use to give you the best color viewing. Two prominent color management systems include ColorSync for the Mac OS and ICM for Windows 98 and 2000.

While Gamma isn’t perfect, it will get you into the ballpark. Once again, the better the color, the more picky you may become. The secret in pursuing the quest is not to hunt until the color dragon is slain but until you are satisfied, considering how much it has cost so far, with the match between monitor and print. One of the least expensive ways to calibrate your monitor is by using ColorVision’s www.colorcal.com Monitor Spyder. This is a Plexiglas and metal device that attaches to your monitor. When used with ColorVision’s software, such as PhotoCal or OptiCal, it’s relatively simple to calibrate your monitor. This combination of hardware and software can calibrate any CRT monitor, and will produce ICC (International Color Consortium) www.color.org profiles for Mac OS and Windows color-management systems. Depending on what software you prefer and where you buy it, the Monitor Spyder sells for $199 or $399. (Tip: ColorVision’s Web site is the most expensive source for this product.) I purchased a Monitor Spyder and PhotoCal software and found it easy to use. Environmental factors gave me a too-red profile until I fashioned a homemade monitor hood out of neutral gray cardboard. This shielded the Spyder and screen from colored light pouring though translucent green window blinds.

Monaco Systems www.monacosys.com offers a color-management package that includes MonacoPROOF software and X-Rite’s Digital Swatchbook spectrophotometer for $229. Digital Swatchbook works with Macintosh or Windows computers, using measured spectrophotometer readings for color-managing desktop computers. MonacoPROOF builds custom ICC profiles to let you obtain accurate color from scanners, digital cameras, monitors, printers, and even color copiers. The software has a wizard-like interface that guides users through the profiling process and displays on-screen images accurately to produce “soft” proofs.

Some devices, such as the Epson www.epson.com Stylus Photo Color 1280, bundle a copy of Monaco EZcolor Lite that lets you create a single monitor profile for your system.

In addition to Adobe Gamma, there are other software-only solutions you can try. ColorBlade from Studion www.studion.com is a Mac OS-only, Photoshop-compatible plug-in designed for photographers and designers who want no-fuss color management. These folks are rightly tired of color management software geared toward prepress because it is too time-consuming. ColorBlade’s goal is to deliver a WYSIWYG appearance-matched color that’s accurate, consistent, and reliable.

Studion’s SAME (Studion Appearance Matching environment) appearance-matching technology is a ColorSync-compatible color-matching module. It’s capable of generating color separations and previews, as well as colors that remain stable despite fluctuations in ink density and dot gain. You can download a demo version at www.studion.com or look for it on the Adobe Photoshop 6.0 CD-ROM.

Output solutions

After you’ve tried one of the monitor calibration methods, you may find that while your on-screen image and output are a much closer match, they are not quite the same. (Don’t forget differences in reflective and transmitted light and the possibility of metamerism.) In my own case, after happily using Adobe Gamma for many years, I purchased ColorVision’s Monitor Spyder and PhotoCal software. The result was that output from my Epson Stylus Photo 1270 and 1280 printers looked better than it did on screen. But if this is not the case for you and you’re still not happy with your prints, it’s time to look at output profiling.

There are two kinds of people in this desktop darkroom; those who need output profiles and those who don’t. Let’s look at these types of computer users:

When using inkjet or even laser output as a proofing medium, prepress users know output profiling is critical. The client, who doesn’t know anything about metamerism or Lord Kelvin (see sidebar), expects the off-the-press product to look just like the proof the designer shows them. Creatives who use inkjet output as the final product have different needs from prepress users. All these people need is for the prints to match their monitor or their original vision of how the image should appear-what Ansel Adams called previsualization.

Prepress users need slightly more expensive solutions to their color problems, and there is help available from some of the companies that provide input solutions. A great companion to ColorVision’s Spyder Monitor is its Profiler RGB software, which is one of the neatest ways I’ve found for color-managing a desktop printer. ColorVision provides target files that you output on your printer. After you digitize that output with your scanner, Profiler RGB compares your image with the original file and creates a unique profile for a specific paper/ink/printer combination. If you’re serious about color management, you might want to check out two other ColorVision products.

Doctor Pro software lets you edit RGB and CMYK printer files and uses Photoshop’s capabilities to create adjustment scripts for editing output profiles, including color cast removal, opening shadows, and correcting color mismatches-as well as adjusting brightness, saturation, and contrast. Doctor Pro costs $299. Profiler Pro, an instrument-based calibration software for RGB printers, supports a variety of spectrophotometers and colorimeters. It sells for $899.

If you use ink-jet printers for your final output, you have several software options, including two useful Photoshop-compatible plug-ins. Vivid Details www.vividdetails.com Test Strip 3 functions the same way a traditional darkroom worker might produce a test strip. Printing a digital test proof shows what the image looks like with user-specified increments of additional cyan, magenta, yellow, and black (CMYK), or red, green, and blue (RGB), so you can see how much of what color to add in the printer driver to get output matching your previsualization.

Something new for version 3 is the Metamorphosis feature, a guided system that corrects images based on a user’s response to a series of side-by side, on-screen comparison images generated from your original photograph. All you have to do is click the image you prefer and keep making choices until the software figures out what you want and produces the finished version. Another feature that creatives are sure to like is Gels, which allows you to color-correct all or part of an image by dragging up to nine independent and even overlapping, resizable translucent windows over specific areas you want to color correct.

Extensis www.extensis.com Intellihance Pro 4 offers some similar capabilities within the context of its interface. Both plug-ins are available in Mac OS or Windows versions, and you can download trial versions from their respective Web sites.

Black and white in color

One of the biggest challenges in color-managing output is printing black-and-white images. This is especially a problem with inkjet printers, because the most you get by using colored inks is cool- or warm-toned output-metamerism rears its colorful head when you use pigmented inks (such as the Epson Stylus Photo 2000P) . You can always print using black ink only, and I have successfully produced output this way, but the results depend on the original image. To get truly continuous-tone black-and-white output, you need a grayscale inkset. These replacement inksets and complementary software are available from companies such as Lyson www.Lyson.com and Cone Editions Press. www.piezography.com. These companies offer archival-quality inks that, when used with acid-free paper, produce museum-quality gicleƩ images that can be sold in art galleries anywhere in the world.

Lord Kelvin to the rescue

Long before Edison invented the incandescent light, Lord Kelvin, proposed a temperature scale suitable for measuring low temperatures. During the 19th century, he suggested that an absolute-zero temperature should be the basis for his scale. Lord Kelvin’s idea was to eliminate the use of negative values when measuring low temperatures with either the Fahrenheit or Celsius scales. In honor of his contributions, this system is called the Kelvin scale and uses the unit “Kelvin” or sometime just “K.” The color temperature emitted by light sources is measured in degrees on the Kelvin scale. The sun, at noon on a clear day, measures 5,500 degrees Kelvin. On an overcast day, the color temperature of light rises to 6,700 degrees Kelvin, while 9,000 degrees Kelvin is what you’ll experience in open shade on a clear day. These higher-color temperatures are at the cool (or blue) end of the spectrum. On the lower side, however, light sources are on the warmer end of the spectrum. Photoflood lights and lights used by videographers have a Kelvin temperature of 3,200 degrees. Household light bulbs are close to that color temperature and measure about 2,600 degrees. A sunrise may be well down on the Kelvin scale–about 1,800 degrees.

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