ChromaPure with SpyderX PRO Colorimeter The SpyderX colorimeter is by far the best Spyder colorimeter that DataColor has ever offered. It provides massive improvements in speed and low-light sensitivity over previous Spyders. For a full review of the SpyderX colorimeter, see our Test Center review. It is also an easy device to use because it requires neither a dark reading calibration nor external drivers (support is built-in to Windows). Despite this, it is an affordable mass-market device whose tolerances fall short of professional color analyzers. We have developed a version of the SpyderX, which we have named the SpyderX PRO , that offers substantially enhanced color accuracy across a wide range of displays. NOTE: DataColor offers different versions of SpyderX monitor calibration packages, one of which they Call SpyderX Pro. This is unrelated to what we do. The various DataColor packages differ only in software and accessories. The meter is exactly the same in all. Using a professional 2nm Spectroradiometer, we correct each SpyderX for 13 different display types. These corrections are built-in to the ChromaPure license file. When you initialize the meter within ChromaPure you are asked to select the measurement mode that represent the display types for which the meter has been corrected. Selecting a measurement mode automatically applies the appropriate correction. This way, the $169 colorimeter can approach the accuracy of a $13,000 2nm spectroradiometer. To understand more about this, it is important to first understand the source of errors in tristimulus colorimeters. In an attempt to accurately model human color vision, in 1931 the CIE defined the standard observer, which is characterized by three color matching functions, shown below. A filter-based colorimeter attempts to mimic human color perception by matching these curves. However, accurately matching these complex curves using any reasonably affordable filters requires correction with a reference spectroradiometer. Otherwise, you cannot achieve the desired accuracy with different display types. A spectroradiometer does not rely on filters as a way of mimicking human color vision, but rather measures the spectra of a display directly. Its accuracy depends only on the bandwidth, sensitivity, and resolution of the device. The inaccuracies of a filter-based colorimeter arise from a variety of sources.
Taken together, these four sources of inaccuracy—generic factory calibration, unit-to-unit variation, effects from aging, and a lack of consistency among displays—result in a device that, on average according to our tests, typically deviates from a reference spectroradiometer up to about 5-6 dE (CIELAB). Our PRO version of the meter will cut this source of error considerably. The SpyderX PRO virtually eliminates 3 of the 4 sources of error and lessens the fourth for a small fraction of the cost of a true reference device. Of course, the best way to minimize these errors is to use your own reference spectroradiometer to correct the meter for each calibration session on a single display. ChromaPure provides a Meter Correction module for just this purpose. However, the vast majority of consumers cannot afford a true reference device, which are very expensive. SMPTE requires a reference instrument to have a minimum accuracy of ±0.002 for the measurement of xy chromaticity coordinates at any luminance above 3 fL. The only instrument capable of this level of precision is a 5nm or better spectroradiometer. A tristimulus colorimeter will not offer this level of accuracy, nor will an 8nm or 10nm spectroradiometer.
The SpyderX's accuracy is reasonably consistent when reading CRTs, plasmas, and front projector screens. The biggest problem by far lies with LCDs. Using the Standard mode the SpyderX may read one LCD very accurately and yet be off on another. It is difficult to achieve consistency when reading LCDs. Contrary to one widely-repeated myth, this is not an issue directly related to the difference between CCFL backlit and LED backlit displays. Some LED displays actually give the colorimeters less trouble than their CCFL counterparts. Also, the SpyderX can maintain considerably different levels of accuracy when comparing two CCFL displays. The problem isn't with LED backlighting. The problem is LCDs period. To address this problem, the SpyderX PRO ships with 8 different LCD modes. We may add additional LCD modes as needed.
|