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Color Management - The Color Conundrum
by Scott BourneI hate digital! Those were the words that escaped out of my mouth in 1992. I was trying to color match the prints coming off of my Apple Macintosh onto my first dye sub printer. Back then, we didn't have a digital camera, but we had a scanner. Color matching became something I feared worse than an IRS audit.
Rather than give up, I have devoted much of the last 13 years to perfecting simple steps that will lead to predictable color nearly every time I print a digital image. Did I succeed? No. At the consumer price point there is no such thing as "perfect color." I do not believe any process costing less than $10,000, digital or analog can guarantee you "perfect" color. But with the right tools, a good eye and some patience, you can generate consistently "predictable" color on nearly any printer. And that's what color management is really all about. Generating consistent, predictable results.
Don't get me wrong. In most cases, the color match looks NEARLY perfect, if not perfect. The problem is that your version of perfect and mine might differ depending on our use for the images. A person selling shirts in a catalog needs REALLY perfect color matches. Otherwise, the customer who buys a cyan shirt only to find out that it's actually light blue will be disappointed.
So let's get the first key to "predictable" color.
COLORSYNC
It all starts with Colorsync--Apple's Colorsync that is. (Don't worry Windows users, it works on PCs too.) A piece of software that ensures input, output and editing software will see eye-to-eye on color and, deliver predictable results every time. At the heart of Colorsync are special files called device profiles. These files describe the capability of each component in the chain of workflow.
What makes Colorsync work is a file format developed by the International Color Consortium (ICC). Accordingly, you will hear a lot about ICC profiles.
IT'S THE MONITOR STUPID
During those early years of digital dumbness, I constantly tweaked my scanner and printer to get predictable color. In doing that, I missed the most important component of the process--the monitor. Display calibration is the critical first step in ensuring accurate color reproduction. There are several methods that you can use in order to calibrate your monitor. You can use Photoshop's built-in calibration utility called Adobe Gamma. You can also use Apple's calibration utility (If you're on a Mac) or a third-party software utility. You can also add a hardware colorimeter to the mix to dramatically increase your chances of getting an accurate profile. But to really understand the color matching process, you need to know more than what software to use. You need to know how monitors work.
Computer monitors display colors using the RGB or Red, Green and Blue color space. The first crucial step to getting a good monitor calibration is to use advanced tristimulus colorimeter technology (otherwise known as a hardware screen calibrator) to measure the colors produced by the individual electron guns on your monitor. It is not enough to use a generic profile for the brand or model of monitor you use. This is because all monitors, even those made by the same company, have slight color variations. Also, since the phosphors that make the image on your screen degrade or change over time, constant recalibration (I recommend every two to three weeks) is required to keep the monitor fully profiled. (NOTE: The preceding paragraph applies to CRTs only. LCDs work differently.)
I have tried several devices and most work well. The problem is that until now, the average photographer couldn't afford most of the hardware devices sold to measure monitor calibration.
CALIBRATION
It sounds like a medical term but calibration is actually the process of setting a device (e.g., a computer monitor) to a known state of behavior. In conjunction with calibration you create a profile of your specific monitor. The profile compares the monitor's actual color handling capability to the calibration points.
To accomplish these tasks, I use the MonacoOPTIX-XR Pro Edition calibration system. (Available from B&H Photo at www.bhphoto.com.) It includes a hardware device generically known as a spyder. This is a device that you suction onto the front of your computer monitor if you use a CRT and that you hang in front of your monitor if you use an LCD. Then, using software, the spyder accurately reads the gamma of your individual monitor and creates the all-important ICC profile. This profile communicates directly with Photoshop, your monitor, scanner and printer to manage the color process. Obviously, the ICC profile must accurately describe your specific monitor before you can reliably produce a print that matches what you see on the screen.
Principal to identifying the monitor's color space is the ability to recognize color properly. While many photographers will use the Adobe Gamma facility inside Photoshop, this system is not intuitive and is subject to problems caused by ambient light. By using the software that comes with the spyder, you create a completely accurate profile. Simply following the steps listed on the screen will help you get a reliable ICC profile in about five minutes. (NOTE: While not required, I suggest setting the lights in your office during the calibration period to match the light that you will actually work in. Note that ambient light impacts how you see color on a monitor and in turn, how the spyder will see it as well.)
PHOTOSHOP'S TURN
Now that you have completed and saved your monitor calibration, Photoshop will automatically recognize it. But in order for that to mean anything, you need to set a few commands and controls in your Photoshop preference dialog box that will help the profile process generate predictable color. The description of the color space you will work in is the key point in this procedure. The RGB setup dialog box will let you choose a color space. You might be saying to yourself, "Why have more than one color space?" Well, each monitor is different, and some can take better advantage of color than others.
Likewise, output is an issue. For instance, colors displayed on the Internet are not as vibrant as they are on a glossy print. So Photoshop gives you the option of selecting the color space that most closely matches your goals. Generally, you will be working on images that will be displayed as prints or slides or on the web. For prints and slides, I suggest that you select the Adobe RGB (1998) color space. It has the broadest printing gamut. If you shoot exclusively for the web, choose sRGB.
Once you have made your choice, save the RGB setup to your Colorsync Profiles folder. On some systems this will happen automatically. On others, you may have to select the folder.
PRINTER AND SCANNER PROFILES
But what about your printer and scanner? How do they fit in to the equation? Here it gets a little tricky because there are so many combinations. I will assume that you are scanning slides or film. Either way, the scanner you use will typically come with its own ICC profiles. These are sometimes shipped with a set of files known as film terms. Film terms are specific guidelines for density and color on specific films. Combining the right film terms with the ICC profiles shipped with your scanner will usually be the most affordable way to get the scanner hooked into the digital workflow. While there is profile software available for scanners, these products are very expensive and do not yield results that are significantly better than using the manufacturer's ICC profiles.
Also, the scanner is the least important item in the chain to profile, so that is another argument for going with standard files shipped with the unit. Also, the newer and more expensive your scanner is, the more likely it will fit into a great color management system.
The printer is another story. Most photographers are using ink jet printers these days, and Epson seems to have the lion's share of the desktop market with the 1280, 2200 and 4000. Each of these printers ships with a set of ICC profiles that the user can select when making prints. Always check with the printer manufacturer for updated printer drivers that may contain new ink/paper/printer profiles.
That brings up another point. You have to change your ICC profile if you use inks other than those from the printer's manufacturer. Many of you are experimenting with archival inks. While this may make prints more salable, it creates chaos with the existing printer profiles. My advice is to stick with manufacturer's ink during the printer warranty period. Only change if you are sure that the ink supplier can provide you with accurate and updated ICC profiles.
Printers are also calibrated according to the paper they use. In other words, an Epson 1280 printing on Epson Photo Gloss paper will use a different ICC profile than an Epson 1280 printing on heavy matte paper. Always be sure to match your paper to your ICC profile. Don't buy exotic papers that have not been profiled unless you want to pay to experiment.
You can make your own profiles if you are an advanced user.
BRINGING IT ALL TOGETHER
So you have the right tools, and you want to know the sequence? Just remember these steps;
1) Calibrate the monitor first.
2) Then set your color workspace in Photoshop.
3) Select an ICC profile that matches your printer, ink and paper.
4) Print.
Away you go. Most systems require just a bit of tweaking but using the tools and the methods described above should give you a good color match every time.
Article Copyright 2005, Scott Bourne - Photofocus Magazine
About the Author
Scott Bourne is the author of "88 Secrets to Selling & Publishing Your Photography" and "88 Secrets to Photoshop for Photographers." Both are available from Olympic Mountain School Press, http://www.mountainschoolpress.com His work has also appeared in books, magazines, galleries, calendars, on greeting cards, web sites and on posters.
Scott is a professional photographer, author, teacher and pioneer in the digital imaging field. His career started in the early 70s as a stringer covering motor sports for Associated Press in Indiana. Since then, he has shot commercial, portrait, wedding, magazine and fine art assignments. His new passion is wildlife photography.
Scott regularly lectures on a variety of photo and media-related subjects. He's appeared on national television and radio programs and has written columns for several national magazines. He is the publisher of Photofocus.com, an online magazine for serious photographers and also serves as the executive director of the Olympic Mountain School of Photography in Gig Harbor, WA.
Article Source: http://www.bigarticles.com
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