Dear Ms. DesMarteau,
Regarding the article "An Enlightening Experience: Standardizing the Color Evaluation Process" by David Albrecht, GTI, published in your February issue and on your Web site, I am very concerned that you published an article that references inaccurate facts and figures. Mr. Albrecht also makes editorially biased statements that are more opinion than fact. We find these unsubstantiated remarks misleading to your readers and damaging to GretagMacbeth (GMB).
For example, Mr. Albrecht describes filtered tungsten halogen as "old technology." While it may have been used for many years, it is not an "old technology" as the author describes, but an alternative technology designed for specific color critical applications. It is a technology that is so accurate that the majority of the world's leading apparel companies require it for their supply chains and business partners. Many of these apparel companies and suppliers are your readers.
The author's statement regarding "quoted standards" is misleading. In fact, numerous standards specifically designate filtered tungsten technology. The comments from Mr. Albrecht regarding the ASTM standard are taken out of context. ASTM D1729 2003 states a CIE assessment of BC or better. The standard goes on to warn the user that neither correlated color temperature nor chromaticity are qualifications for rating simulated daylight and that attention must be paid to the spectral distribution of the daylight source. Fluorescent daylight, especially 3 and 4 phosphor lamp technology, does not provide the proper spectral distribution and cannot achieve a CIE assessment of better than B in the visible portion of the spectrum. Filtering a tungsten halogen lamp will consistently provide the minimum CIE assessment and in most cases better it with a rating of A -- something to date that is unachievable by fluorescent technology.
In addition, while other standards like SAE J361, BS 950, AS 4004 and DIN allow at a minimum a B CIE rating, they strongly recommend an A rating for critical color judgments. Specifically because these booths are used for critical color judgments, the world's leading apparel companies require suppliers to maintain the booths properly. Purchasing certified lamps, as the author suggested, does nothing to ensure the complete booth operates correctly or provide certification of its performance.
Finally, the writer provided incorrect and misleading information in quoting cost-of-ownership figures. The author neglected to mention that the "periodic" filter replacement is only recommended every five years and is only based on reading the specific light booth's performance. Further, supplier compliance programs offer significant price savings for most users.
There is also a fundamental reason for the cost difference between the two technologies. The filtered tungsten is more accurate and much more highly rated at color rendering than the fluorescent technology described by Mr. Albrecht. Most apparel companies feel it is a worthwhile investment.
GMB, as the leading supplier of lighting booths to the textile industry, is disappointed that a major publication, such as Apparel Magazine, would publish an article without ensuring the accuracy of the technical information. Please know that GMB's color experts can offer you assistance in better understanding color technology and ensuring the accuracy of your articles.
Ray Frugia, Product Manager, Lighting, GretagMacbeth LLC, New Windsor, NY
Editor's Note: David Albrecht, author of the article referenced above, will offer a response to this letter in next month's issue.