Plato said that art is thrice removed from reality.
Plato said that art is thrice removed from reality.Although the philosopher wasn’t a photographer, he hit the nail right on the head where digital imaging is concerned. If we follow what happens to the color of an object during the photographic process—from capture through output—we see several junctures where the colors are likely to be changed unintentionally, and we can gain a better understanding of why it’s important to use calibrated devices.
Take a yellow daisy growing in a sunlit field, for example. We use a camera to capture a digital image and our brain to record a memory of the color. Scientists believe that no two people see colors exactly alike, so from the very beginning our “art” becomes separated from reality. Human perception is heavily influenced by physiological and psychological factors. Long story told short, attempting to accurately judge colors simply by looking at them is futile.
All digital cameras render colors slightly differently, too. This happens because all digital signal-processing engines—the computer “brains” inside cameras—have specific color biases. Shooting RAW format is a step in the right direction, but doesn’t solve the problem completely because differences in lens coating and construction influence color rendition. In some cases, these variations are slight, but in certain situations they can be enormous. In every case, the original color can be restored on the computer—and that’s where it starts to get complicated.
There are ways to objectively measure color, but few photographers do this. Instead, they rely on experience and personal taste when adjusting the colors in the digital image to match the original hue, chroma and lightness of the colors in the object. That’s all part of the creative process. However, even the sharpest eyes in the world can’t accurately evaluate color unless it’s being viewed on a computer monitor that has been calibrated. And if it’s accurate color prints you’re after, your printer must be calibrated as well.
Digital cameras, computer monitors and color printers each use specific color spaces. Color space describes a range, or gamut, of colors. All digital cameras can capture images in standard RGB color space. Some cameras offer Adobe RGB (1998) as an alternative. Standard RGB, or sRGB, was defined by Microsoft and HP and popularized as a standard to assure that colors would appear approximately correct when viewed on a typical computer monitor. Adobe RGB was introduced to include the colors that can be printed using CMYK inks—even though it uses only the three primary colors. This is important when images are printed on commercial presses.
Unless the color spaces are correctly mapped from device to device, the colors won’t match. Even if you’re using the published color profiles for your LCD monitor and inkjet printer, you can’t expect to produce consistent, predictable results unless both have been calibrated. Calibration produces ICC color profiles that communicate how colors should be mapped from the color space of the input device to the color space of the output device. The critical starting point is the map that specifies how the colors should be reproduced on your color monitor. But if your monitor isn’t calibrated, you won’t be able to see an accurate rendition of the colors, even if the software is correctly translating one device’s profile to another. Consequently, once again, it’s impossible to make adjustments that are meaningful or reliable on an uncalibrated monitor.
To achieve complete color calibration, you need the right tools. A typical configuration consists of one piece of hardware—a colorimeter—and a software suite. A colorimeter is a sensitive, high-precision light meter that resembles a high-tech hockey puck. It’s powered by a cable that connects to your computer via a USB port. The cable drapes over the back of your monitor and the colorimeter hangs suspended on the monitor’s face like a rappelling mountain climber. There’s a counterweight that allows you to hold it securely in a stationary position so that it can analyze your monitor output with absolute objectivity. The software provides the tools you need to tweak the colors until they zero in on the standard values. Additional applications enable printer calibration.
All display devices, whether CRT, LCD or plasma, suffer from color drift and other phenomena that make it necessary for you to perform the calibration procedure about once a month. The adjustment schedule has little to do with the cost or quality of the display device; it’s more dependent on inherent physical limitations. So once you’ve calibrated your system, don’t sell the colorimeter on eBay—you’ll need to do it again in about 30 days.
Both Datacolor (www.datacolor.com) and X-Rite (www.xrite.com) offer complete solutions that allow you to achieve professional color management throughout the entire process.
The SpyderPRO series from Datacolor has been the de facto standard for professional photographers for years because of its rock-solid reliability and ease of use. The Spyder3PRO continues that trend. The hardware sets the example for all colorimeters—a precise sensor housed in a durable, attractive surface glider that includes a counterweight to maximize positioning accuracy. The software is intuitively easy and can be used with all CRT, LCD and notebook computer displays.
Compatible with Windows and Mac platforms, the Spyder3PRO software package offers a wizard-style interface supported by comprehensive help screens that keep you on track. The software is sophisticated, but photographer-friendly. The Spyder3PRO offers unlimited gamma and color-temperature options and an exclusive automated black and white luminance adjustment feature that delivers exceptionally consistent calibration results. Help
ful before-and-after viewing features let you compare your display’s characteristics with and without calibration. If you’re not a believer in the beginning, you’ll become one after you make these comparisons. The Spyder3PRO also calibrates LCD and DLP front projectors, so your theater presentations will look great, too.
Datacolor’s exclusive PreciseLight technology allows you to take room light into consideration, so you can accurately balance your monitor under virtually any ambient lighting conditions. Other features include multiple-monitor calibration and matching, with custom targeting and curves manipulation. The Spyder3PRO kit also includes a software-based profiling tool that allows you to create custom printer profiles without using a third-party scanner. Estimated Street Price: $249.
A colorimeter is a sensitive, high-precision light meter that resembles a high-tech hockey puck.
X-Rite i1 Display 2
X-Rite, which recently acquired venerable GretagMacbeth, is a major player in the color-management arena and offers a broad range of hardware, software and services for measuring color. For professional photographers, X-Rite offers a broad range of calibration products at several price points. Central to its color-management line is the i1 Display 2 (read eye-one display two) colorimeter, a precision sensor that delivers a very high degree of accuracy (within about 250 degrees Kelvin, plus or minus).
The X-Rite i1 Display 2 system includes i1 Match 3.6, a powerful software package that provides an intuitive interface and supreme simplicity in the Easy Mode (it delivers accurate results with just a few mouse clicks) and an Advanced Mode that offers enhanced features and more complete control. You can achieve improved color management on multiple monitors, thanks to user-definable luminance settings, and advanced gray balance optimization delivers better gray renditions. And you can view before and after images so you can easily compare the results of your calibration efforts.
The system features an exclusive ambient light head to capture ambient light measurements. It’s detachable and also serves as a dust cover—very clever. If you own a monitor that’s DDC/CI (Display Data Channel/Command Interface)-compliant—like the NEC MultiSync 2060NX, for example—you can enjoy one-push calibration. A complete listing of supported monitors can be found on the X-Rite Website. Estimated Street Price: $249.