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Rangefinder
Magazine ICC Profiles: by Stan Sholik
Achieving accurate color output has always been a challenge for photographers. Even before digital files, photographers exposed color negative or color transparency film and worried about achieving an output color balance that would please their clients. For film photographers, the result was highly dependent on their choice of lab for processing and in the case of color negative, printing. Capturing digital files throws different variables into the mix. To achieve accurate output color, it is necessary to take steps much earlier in the photographic process and to follow an established color-managed workflow all through the process. An image that looks great on one monitor can look somewhat different on another and totally different when it is printed. While dealing with digital color has become much easier in the last few years, there are still obstacles to overcome and refinements to be made. It may no longer be the rocket science it once was, but there are still complex issues to deal with and sophisticated software to master. Fortunately, as the process has become more manageable, photographers have become more knowledgeable.
While photographers obviously want to produce the best digital files they can, color management is very much customer driven. Art directors, corporate imaging departments and commercial printers want color-accurate pictures with which to work. As more and more clients add color management to their production workflow, photographers have to have color management capabilities in their studio workflow to meet the demands of those customers. Color-managed customers expect photographers to produce output to match what they see on their monitors. Even photographers outputting images on their own in-house printers have much to gain from a color-managed workflow. For those photographers that haven’t implemented full color management in their studio, there are a number of options available. These range from color management software packages with “wizard” interfaces, to software that walks the user through the process, to profiling services that will create custom profiles for imaging labs. Color management is based on the interaction of a number of components: profiles; Color Management Modules (CMMs); and the CMS or Color Management Solution, such as Apple’s ColorSync or Microsoft’s ICM (Integrated Color Management), built into the operating system. There are two broad-based types of color profiles. Device-specific profiles, which are used to profiles individual pieces of equipment, and device-independent profiles (the CMMs), which make it possible to link device dependent profiles, and, in turn, diverse devices. There are programs that manage the entire color management process, and there are programs available that are primarily concerned with profiling (or “characterizing”) a device such as a digital camera, monitor, scanner or printer. Device-dependent profiles are unique files that contain information describing the specific characteristics of a device. These characteristics are determined by measuring the device’s output against a known standard.
A monitor profile, for example, is created by using a hardware device, either a colorimeter or a more sophisticated spectrophotometer, to compare the color values displayed on the screen to the known values generated by the software. In the case of a scanner, known values of a standard target are compared with the values from the output of the scanned target. And finally, in the case of print output, a profiled scanner or a spectrophotometer measures the printed output of a software-generated target and compares the color values against the known target values to create the profile. Before a device can be profiled, it must be brought to a known state and this state cannot change or the profile will no longer be valid. This process is called “calibration.” Color management software also handles this task, instructing or aiding the user to set color temperature and gamma for a monitor, for example. For scanners and printers, calibration can sometimes be as simple as ensuring that all internal automatic color adjustments of the device are turned off. More sophisticated, and more expensive, color management software packages offer more options for calibrating devices and significantly more sophisticated profiling capabilities. They also offer the ability to edit the profiles to “tweak” them for that final bit of color correction that is often needed to optimize output. There are a variety of color management programs available (see pg. 92). The profiling process is fairly similar among color management programs. What distinguishes them is the types and quantity of different devices they support, their ease or complexity of use, and the final quality of the profiles they generate. The cost of many packages is now well under $500, although the most complete software and hardware bundles that include high-end spectrophotometers can cost four or five times that much or more. Of particular interest to photographers is the increasing availability of software for digital camera profiling. All professional-level digital cameras convert and tag each file with a color space, such as sRGB or Adobe RGB. While most high-end digital backs are individually profiled, for other cameras this process generally assumes a generic profile for the sensor and the conversion to the chosen color space.
For these cameras, and even for some high-end digital backs, color accuracy can be improved by creating a camera profile for a particular set of lighting conditions. This involves shooting a reference target, such as a GretagMacbeth ColorChecker or ColorChecker DC chart, opening it in the software and creating a profile—very much the same process as creating a profile for a scanner. Even with the wide variety of off-the-shelf tools available, some photographers would rather not spend the time and effort required for professional-level color management. For these firms, there are a number of other options available. These options range from hiring an outside consultant to purchasing ready-made generic profiles on the Internet to purchasing custom profiles for their output equipment. Color management consulting firms have grown up around the country. Many were begun by veterans of the printing industry to serve their needs, but are now working with professional photographers and photo labs. One such person is Bruce Bayne of Alder Technology (www.aldertech.com) in Oregon. He consults with clients on their needs, sells the appropriate hardware and software and trains them on its use and how it ties into their workflow. Because color management can require some handholding, it is best to look for a consultant in the local area. Rates for this type of service are typically $1500 per day plus expenses. Custom profiling services for in-house printing are also available on-line. This type of service is important if you intend to deliver a hard-copy proof to your client. Profile City, now a part of CHROMix Corporation’s Color Valet service (www.chromix.com), offers a $99 profiling service. Clients download a profile target, output this target on their printer/paper combination, and mail it to CHROMix. CHROMix reads the output and e-mails back a custom profile. Whether photographers decide to create profiles themselves or have an outside consultant or service create them, ICC profiling is an essential part of a color-managed workflow. And a color-managed workflow is essential to achieving predictable and repeatable output to keep customers satisfied and coming back. Stan Sholik is a contributing writer for NewsWatch Feature Service. He is also a commercial photographer with over 30 years of large format studio and location experience.
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