MAURY WRIGHT questions SHIRLEY COYLE, new IES president and president of Cree Canada, on the forward direction of the lighting organization and on key issues such as outdoor lighting preference, glare, flicker, and color metrics.
The Illuminating Engineering Society (IES) is a critically important organization to the solid-state lighting (SSL) industry, guiding lighting practitioners in areas ranging from LED component testing to outdoor lighting design. Cree Canada president Shirley Coyle has also taken on the role of IES president at a time when the organization is witnessing the revolutionary change to LED sources that in turn have raised many contentious issues in areas such as flicker, glare, and color metrics. LEDs Magazine took the opportunity of Coyle assuming the IES presidency to ask about the state of the lighting industry, and the position of the IES and Cree on critical issues.
LEDs Magazine: You take the reins of the IES at one of the most exciting, and perhaps contentious, times in the history of lighting. LEDs have delivered amazing new capabilities but some remain concerned about the safety of LED sources, and there are battles over things like flicker and cool color temperature. What is your outlook on the industry and what are your goals for the IES?
Shirley Coyle: We are in such an exciting time in the history of lighting — not only in terms of technology, but also in terms of research related to the non-visual effects of lighting. We are moving beyond LED lighting as simply an energy-saving, long-lasting light source, to unlocking its real value to achieve previously unimagined capabilities — connecting lighting systems to users and operators in interior spaces, and in outdoor environments providing intelligent light — better light.
My goals for the IES in the next year include delivering on the recommended key changes raised in the IES comprehensive business review, which was completed last year. With our new executive vice president Tim Licitra on board now for eight months, we have already moved on building our technical, industry relations, and education staff to better support our key strategic pillars. Other operational improvements coming soon include the implementation of an Association Management System (AMS), along with a new website and other online tools, that will seamlessly support the individual IES member, our Technical Committees as they produce standards documents, our Non-Technical Committees (conference planning, awards, etc.), and the many hardworking volunteers managing their local IES Sections in Canada, Mexico, and the US.
LEDs: We’d like to discuss some particular contentious issues. There have been a number of high-profile instances where citizens and municipalities have demanded that only warm-CCT outdoor lighting be installed. Organizations such as the International Dark Sky Association have long been in favor of such a CCT limit. And now the American Medical Association (AMA) has even provided unsolicited input on the topic. Meanwhile, it’s the IES that is doing the due diligence in research and trying to balance safety for pedestrians and drivers at night. What is your outlook from the IES perspective on the topic?
Coyle: The IES is reviewing the AMA report and will be issuing a technical response soon. It’s really important to us that we are 1) thorough, 2) accurate, and 3) holistic in our response. Our position on the AMA weighing in on this matter is that, as the IES and AMA are organizations who both have at their core the interest of the general public, the public would have been better served if the AMA had made an attempt to collaborate with us when they first initiated the effort to update their 2012 report.
LEDs: Do you think that the public outcry for warmer CCTs is more about CCT and spectral power distribution (SPD) or more about either poor luminaire design or poor lighting design at specific sites?
Coyle: It seems that some parties like to blame lighting color, even if it’s really an issue of poor luminaire or lighting design. There are far higher CCT LED installations with no complaints than there are with complaints, but when complaints do occur, the color difference between the old source such as high-pressure sodium (HPS) versus the LEDs is an easily identified target. In addition to selecting a CCT that is appropriate to the client and application, it’s really important to use well-designed luminaires that minimize glare. The other critical task is to ensure that a lighting design is done to meet the needs of the client, to meet minimum IES standards and to limit light trespass.
In some cases, the outcry is driven and amplified by those with their own motivations to use warmer CCTs — for these folks, the idea of potential blue light effect on sky glow will trump any other issue. Others target outdoor lighting CCT on the basis of circadian disruption, ignoring the other important aspects of light intensity, duration under the source, and time of day. Arguably, lighting within a home at night or within a night-shift interior workspace would cause more disruption to the circadian cycle through higher intensities and longer durations, than the short-term, low-level lighting experienced in most outdoor applications — making the spectrum of the outdoor lighting a relatively minor issue.
LEDs: Obviously, you also have your responsibilities as the president of Cree Canada and a long career at the company that was probably the first mover in LED-based outdoor lighting for street and area applications. What is the Cree perspective on the controversy?
Coyle: Cree is committed to providing quality light that’s comfortable and doesn’t require the customer to compromise. We have a long history of delivering outdoor lighting, for area and roadway applications, across a range of color temperatures — 3000K to 5700K. What is important to note in the ongoing conversation is that not all LED lighting is created equally, and the technology has reached a point where it can — and should — deliver better experiences, without compromise, in a manner not possible before. Cree’s WaveMax technology is an example of providing low-glare, warm-CCT, dark-sky-friendly illumination.
LEDs: Do you have a personal opinion on the topic of CCT? Is 4000K or 5000K CCT generally safe for people under typical conditions? Do you think people can see better under cooler CCTs, which might enable the ability to lower light output levels?
Coyle: I think personal preference of the client will vary with the application. We often find that warmer 3000K CCT in a well-designed, visually-comfortable streetlight is preferred for residential neighborhoods, while 4000K CCT is preferred for collector roads and highways. On the issue of safety, the most obvious flaw is that CCT is not the issue at all — CCT is an overly simplistic value that describes the color appearance of a light source, and for these issues the important metric to consider is the specific blue content — and more specifically the melanopic response, which cannot be captured in CCT. So there is a disconnect here between real lighting science and those leading the outcry on the basis of CCT.
LEDs: Back to your IES role — we want to ask you about color metrics. From our perspective it has been disappointing in how long it has taken the industry to develop a better metric or metrics despite some excellent work, and it was great to see TM-30 emerge from the IES as a much better metric than CRI. Yet the CIE and even some international lighting associations don’t seem willing to adopt what appears to us as perfectly good work.
Coyle: IES TM-30 was developed for a specific reason, which was to address certain deficiencies of CRI and to develop an alternative approach for the industry to test drive. A Technical Memorandum (TM) by the IES is a document that serves just that purpose — to have a consensus-based document that provides us with new information for consideration, based on good science and applications. The content of a TM might eventually find its way into our Recommended Practice (RP) documents or the IES Handbook. We have issued this TM-30 and it is being reviewed and tested by lighting practitioners in North America. Internationally, the methodology is being reviewed and considered by CIE working groups on color quality metrics. We will collect feedback and see where it goes. There are other metrics we will address as well, using the same approach.
LEDs: There are other metrics that are in the forefront of the lighting industry as well. Outdoors, glare remains an issue. It is understood the light sources can cause both disability and discomfort glare. But there remains little in accepted ways to characterize the problem and perhaps aid specifiers in choosing the right products. What is happening within the IES in the glare area?
Coyle: We have started a new era with our Standards Department, with new leadership and additional staff. The Standards Department is preparing a long-range plan on new standards development, in conjunction with a Strategic Research Plan, which identifies a number of issues for near-term consideration. Glare is one of the top priority topics because it is often cited as an issue, but we lack a proper metric.
LEDs: One last area of contention is flicker, and that is probably more of an issue indoors than out, although it comes into play both places. The IEEE published a standard establishing what many have said are far too strict limits on flicker. What is your or the IES’s position on the IEEE work?
Coyle: Some of our members participated in the IEEE committee that developed the document you reference, and our IES Testing Procedures Committee is looking at this issue now. Considering the precedence of cooperation and a recent memorandum of understanding (MOU) that we have in place with the IEEE on another document, we hope to work collaboratively with them in future developments on this topic.