You Might Be a Display Metrologist If …
In the world of display technology, there are numerous niches, important but specialized areas that stitch together to form a quilt stretching across the continuum. Display metrology is just such a niche, practiced by a few, but properly understood by even fewer. In fact, to be a display metrologist, you need to know a lot more than just how to aim and operate a photometer. You need to understand why that instrument works, and when you can rely on the value it measures — and more importantly, when you cannot.
I would actually suggest that the true metrology portion of display measurement is a niche of a niche, populated by those who regularly say "luminance" instead of "brightness" and can discuss the merits and shortcomings of Fourier optics in the same way many of us would casually debate about CCFL vs. LED backlighting. True display metrologists are the ones who augment $100,000 spectroradiometers with pieces of hand-cut black cardboard because the "stray light" is affecting the measurements. They create innovative solutions to complex problems that properly fit the circumstances and sometimes look too simple to really work. In fact, using the humor brought to the field by our colleague Dr. Edward F. Kelley, it is tempting to develop an almost Jeff Foxworthy-like attitude to the things that metrologists spend their time on. For example, if you can utilize a styrofoam beer cooler as a suitable integrating sphere for reflectance measurements, you might be a display metrologist.
But this is not a fair characterization because it implies that the work is not rigorous or precise. In fact, just the opposite is true. Display metrologists spend their entire careers pursuing two goals: the most precise and accurate measurement of light from displays and finding the best correlation possible between what they measure and what users of the displays actually see. And make no mistake, the accurate measurement of light from displays is no simple task. There are an astounding number of commercial instruments on the market today that even when used as rigorously as possible are not better than ±10% in absolute accuracy. Whether that performance is good enough for the intended application is a real problem with which display metrologists regularly struggle.
As you can imagine, educating users on the right ways to perform measurements has been a challenge as well. People want easy answers to questions such as, "How do I measure that parameter?" and "What number is good enough?" Providing answers to the first question was the goal of a standards group that started working with the Video Electronics Standards Association (VESA) to develop what is now known as the VESA Flat Panel Display Measurement (FPDM) standard. The VESA FPDM is widely recognized as one of the best instruction manuals ever produced on the practical application of optical metrology to displays.
In 2007, this effort took another great step. The team that developed the FPDM has re-organized themselves with the support of the Society for Information Display into the International Committee for Display Metrology (ICDM). The new ICDM is made up of the same team as the FPDM effort, but the process is now totally open to the display community, and their outputs will be offered royalty-free to the entire world. In a smaller way, this new approach is analogous to the effort to develop Linux in the 1980s, where anyone could use any part of the project and add their innovations to it royalty-free for the entire world to use.
A major component of the ICDM education effort is the newly launched Wiki page located at http://wiki.sidmembers.org. This project will be similar to other Wiki efforts where anyone in the community is free to contribute and the pages will become the encyclopedia of everyone's collective knowledge, experience, and new innovations. The best innovations will undoubtedly become part of future versions of ICDM standards. In this case, the ICDM will serve as the moderators of the process, ensuring that everything added to the standard is of the highest quality and suitability for use on displays. By fostering a truly open process where everyone will benefit without regard to commercial interest, the ICDM is making a real positive impact on the display community.
Of course, this is only possible due to the dedicated efforts of the ICDM leadership including Joe Miseli, Ed Kelley, Jongseo Lee, Michael Becker, Andrew Watson, and Paul Boynton. These gentlemen deserve real encouragement and support from all of us to make the ICDM process everything that it can be. You can read much more about the ICDM in Joe Miseli's feature article in this issue of Information Display.
To be fair, I want to mention that the efforts of the ICDM are just a small part of the overall standards activities ongoing in the field of display measurement. Numerous standards organizations, including CIE, IEC, SMPTE, ISO, VESA, EIAJ, and others, also are making great contributions to the body of knowledge to better understand and characterize the performance of displays. There are nowhere near enough pages in 6 month's worth of Information Display to properly catalog all the contributions being made and all the efforts under way. That is not bad for a niche of a niche group within the displays industry.
I also want to introduce to you and personally thank Dr. Michael E. Becker for serving as our Guest Editor for this month. Michael has been a leading contributor to the field of display metrology for countless years and it has been an honor to serve with him on SID committees and learn from him in a variety of circumstances. Be sure to read Michael's guest editorial for his perspective as well as his introductions of this month's feature articles.
Stephen P. Atwood