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Digital Focus
How to Achieve Color Consistency: Why Profiles Take the Guesswork Out of Color Management


R.J. Muna


R.J. Muna


R.J. Muna


R.J. Muna



Ultimately, the goal of a fully color-managed imaging system is to provide color consistency between devices--digital cameras, scanners, monitors and printers--so you get the colors you expect to get.

Color management is based on the premise that when you mathematically describe how a device reproduces color with respect to a uniform standard, you can easily adjust those colors for predictable results.

Do Your Imaging Devices ALL Speak the Same Language?

This essential function in color management is done through the creation and use of profiles. A profile simply describes the colors reproduced by a device, such as a camera, scanner, monitor, inkjet printer, or printing press. It is comprised of mathematical tables and other detailed information that literally quantifies how we "see" color compared to how the device "sees" color.

Profiles also allow different imaging devices to communicate color with each other. Imagine that your monitor might speak French, while your printer speaks German. Profiling each device introduces a common language, say English, and has the ability to translate from French to English, and English to German.

There are two categories of profiles: generalized profiles, commonly referred to as "canned," and "custom" profiles. Typically, canned profiles are included with the software provided with some devices, such as printers, and can be downloaded from the Web. The results often range from decent to poor because canned profiles represent an average of all the devices of its kind. Compare this profile to suit purchased off the rack at a department store: it may fit well or look awful depending on body size and type.

Custom profiles, on the other hand, are made specifically for your device and its current state, much like a custom suit cut just for your body. Even printers produced at the same factory, on the same day, will be never be identical due to a variety of environmental and mechanical conditions. Moreover, your printer will behave differently depending on its age and usage. Therefore, it is always best to create personalized profiles that accurately describe your devices under your specific conditions and current workflow.

The Golden Rule Rules

The golden rule of color management is that every device in your system must have its own profile, canned or custom, so the best possible color can be pulled from all of them to create an optimal image.

Your monitor is the first essential part of your color-managed system. Without an accurately profiled monitor, you have no way of judging the content of a digital file. If a monitor is color accurate, you can make decisions based on what you see. Custom monitor profiles can be built using a colorimeter, a machine that literally reads color patches on the screen and compares them to the known patch values. A great example of this type of product is the Monaco Optix XR.

Printers also need to be profiled, but you can have many different profiles for one printer. Ideally, printer profiles should be made for each specific ink and paper combination used on that printer. For example, a profile made for an Epson 7600 printer using Epson Matte paper would be very different from a profile designed to print on the same printer using Epson Glossy paper.

Printer profiles are generated by printing a specific target of color patches. Then a spectrophotometer reads and measures them. Software compares the printed values to the known values of the target then calculates the difference and builds a custom profile. A spectrophotometer is much more expensive than a colorimeter (approximately $2,000 vs. $300). That said, the newly released Pulse by X-Rite is an excellent value.

Once your digital workflow has been color managed, it is important to maintain it. Monitors and printers drift over time, and new papers and inks are always being introduced, so new printer profiles are necessary. Color management, itself a new field, is growing exponentially, with more accurate components being incorporated into the overall system all the time.

The benefits you'll reap from a color-managed system will far outweigh the time and effort necessary to maintain it.

Advertising photographer RJ Muna (www.rjmuna.com) recently incorporated color management into his own workflow and into his new photography rental space in San Francisco


   







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