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At some point many professionals conclude that their work requires a reference color analyzer. SMPTE has established standards for such a device. It must measure color accurately to within ±0.002 xy at or above 10 cd/m2 and luminance accurately to within ±0.5 cd/m2 for white field measurements. These are very exacting specifications that no tristimulus colorimeter can achieve, at least for chromaticity. For this level of accuracy you must have a 5nm spectroradiometer. Unfortunately, such devices are not cheap. The Photo Research and Minolta reference devices start at about $15,000 and go up to near $30,000. The X-Rite i1Pro is reasonably affordable, but it is a 10nm device that cannot routinely achieve ±0.002 xy accuracy. Furthermore, in addition to being expensive, true reference devices also often suffer from practical limitations. They can be slow and have problems with low-light readings. Recently, a German company JETI Reference Instruments has developed a true reference spectroradiometer, the Specbos 1211, that solves most of these problems. First, it is relatively affordable, that is at least what passes as "affordable" in the context of reference devices. Second, it is speedy even with low luminance sources. In our testing the 1211 reads a 0.7 cd/m2 test pattern in about 13 seconds. Measurements of a 17 cd/m2 level pattern is 3 seconds or less. It is also amazingly compact and portable and includes a nifty laser spotter that allows for accurate aiming. Finally, it provides a built-in sync detector that ensures that readings will always be synchronized with the frequency of the display being measured. This feature guarantees excellent repeatability on all display types. The only feature this incredible device gives up to the established Photo Research and Minolta competitors is stand-alone operation. The Minolta and Photo Research alternatives allow for aiming through optical sights and readouts on a small LCD screen. They are fully functional devices without a PC. In contrast, the JETI device works only when attached to a PC with custom software. The 1211 can be used as a working color analyzer. Its speed and low-light sensitivity make it suitable for any calibration task—except perhaps reading black level—where the light level is so low even the 1211 often cannot cope. Fortunately, very low light levels can be accurately read with quite inexpensive instruments, such as the AEMC CA813 illuminance meter. The Display 3 will read down to about 0.007 cd/m2.
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