NEMA Misrepresents IES TM-30

On November 12 the National Electrical Manufacturers Association (NEMA) published a position paper on IES TM-30-15. The document is here. It seems to be a willful misunderstanding and misrepresentation of TM-30. Here’s how…

The paper opens with NEMA’s support of an improved color metric but then goes on to say that “NEMA opposes any mandatory reporting or performance requirements for IES-Rf or IES-Rg.” This is a strange opening since neither the IES, in general, or TM-30, in specific, is proposing mandatory requirements. In fact, the IES’s own position paper on this states that “As with any IES Technical Memorandum, TM-30-15 is not a required standard.” So the paper begins with alarm about a non-issue.

Next, it says that, “Any single-number fidelity measure (such as Ra or the new Rf) that averages the results of many colors in a light source could possibly have a high numerical value and yet perform poorly with some specific colors.” Exactly. That’s the problem with CRI Ra, only a single number is reported. The great advantage of TM-30 is that in addition to the average fidelity value Rf, the calculation tool allows designers to see 1) the fidelity within color groups, called Hue Angle Bins, that encompass the entire color space 2) the direction of hue shift (if any) as displayed in the Color Vector Graphic, and 3) the Rf for each of the 99 Color Evaluation Samples (CES). Far from being a single value, as with Ra, TM-30 provides designers with layers of additional information about the performance of the lamp in question.

In the next paragraph we are told “The IES-Rg metric can have a value greater than 100 and yet saturation might be lower than the reference light source for certain colors.” Right again, but in a misleading way. As with color fidelity, TM-30’s evaluation of color gamut is layered. Rg represents the average shift in saturation of the 99 CES. If a specifier wants deeper information it is available in the calculation tool as 1) a CES chromaticity comparison that plots the CES under both the reference illuminant and the test source so that one can see the shift 2) a graph showing the change of chroma by Hue Angle Bin.

The entire third paragraph complains that if Rf is 100 there can be no increase or decrease in Rg – saturation is held at 100, too. This is like pointing out that the problem with taking a bath is that you get wet and soapy. The interrelation between Rf and Rg is a feature, not a bug. When the fidelity index of a light source matches it’s reference then OF COURSE they will produce the same saturation of colors. If one wants to purposely increase or decrease saturation the only way to do so is to use a light source that is NOT an exact match to the reference source, and hence one that has a lower fidelity value. The relationship between Rf and Rg are shown as a graph in the calculation tool to help designers visualize the values that the tool calculates. That’s a good thing.

Finally, the paper concludes with “It is premature to consider IES TM-30-15 as a mandatory requirement or regulation because the metrics are likely to evolve.” As I said at the beginning, this is a non-issue.

The IES developed and issued TM-30 because CRI does not consistently and accurately represent the color rendering of many light sources, especially narrow band emitters like LEDs. This issue is well known and completely accepted by the industry, including the CIE. (A list of CRI’s shortcomings is included in the latest edition of the IES Lighting Handbook.) The IES position is that TM-30 “has been developed for the benefit of the lighting community to provide: (a) a more accurate assessment of color fidelity; (b) an additional, complementary assessment of the influence of the preferred color appearance of objects (related to color gamut); and (c) more detailed information about the rendition of specific colors.“ and goes on to say that, “the issuance of TM-30-15 will enable the international lighting community to carefully evaluate it, providing a path leading to improved standards and design guidance. Technical analysis and feedback regarding the method described in TM-30 will be critical to continued development and standardization of color quality metrics.” In other words, “We think this is a good tool. We’re publishing it so that other concerned parties can evaluate it. We hope that this will trigger the acceptance of TM-30 or the development of another tool.”

Clearly NEMA as an organization, or members of their Lighting Systems Division, has a problem with the IES issuing TM-30, but the position paper is a red herring. It stirs up alarm over TM-30 becoming a requirement or regulation when the IES has noted that isn’t the purpose of a TM, and attempts to point out shortcomings that actually belong to CRI, not to TM-30. I don’t know about the politics involved here, but I do know that this paper should be read with skepticism.

Computers in the Classroom

Today’s New York Times tells us about the pernicious effect digital devices can have on our lives, saying that our “digital life keeps us hooked with an infinite entertainment stream as its default setting. Tech companies often set it up that way.” Referred to as growth hacking, it’s the continual testing and tweeking to better hook consumers and keep them coming back. It can be rewarding, although it can also become excessive or an obsession.

I see the result of this in my classroom almost every day with students who are online instead of in class.  I haven’t yet reached the point of prohibiting phones, pads, and laptops from my class, but I’m getting close. Since every classroom now has Wi-Fi it’s not initially clear if a student is taking notes or has mentally checked out of class. Eventually I can tell, though. Excessive typing, looking at the screen but not typing at all, and smiling or laughing at the wrong time are all giveaways that the student is physically present but mentally absent. The problem is that they don’t know that they’re absent, they think they can multi-task and not miss anything. Last semester I added the following to my syllabus, to no avail.

Numerous studies have shown two things about note taking on computers. First, multitasking (such as taking notes while being on social media or answering email) inevitably results in lower quality of notes and reduced information retention, as described here, here and here. Second, the screens of students who are multitasking are irresistible distractions to other students who can see the screen, as described here.

I’m not a Luddite or anti-technology (case-in-point: this blog) but students and educators need to find a way to stay focused on the course material. It’s great that my students can get online during class. If I go to a site as a demonstration or example, they can follow along and bookmark the site for later. However, when students don’t understand or acknowledge the ways in which they’re sabotaging their own education, something has to change. For my part, I’d love to be able to have control over the Wi-Fi network in my classroom so that the only sites my students can visit are those on my preapproved list. Does such a system or software exist?

Who Needs A Lighting Designer?

No I’m not begging for work (although I am available for weddings and bar mitzvahs). At the beginning of every semester I ask my interior design students (especially at Parsons, where the class is an elective) why understanding lighting design is important to them. They tell me that lighting design is important for setting the mood or atmosphere, that lighting affects the appearance of materials and finishes, and that light is an important element in the overall design of any space. Good job!

But, as we move through the semester they often say that there’s so much to know and ask if interior designers, architects, and electrical engineers really know all of it. If not, why do only 10% of construction projects have a lighting designer? Why isn’t a lighting designer assumed to be part of a design team just like an electrical or mechanical engineer?

So I did a little research. According to the DesignIntelligence ranking of the top five interior design programs, only three undergraduate and one graduate program require a semester long course in lighting design. It turns out that I’m in a fairly unique situation in that my undergrad interior design students at Pratt are required to learn about lighting design.

What about architects? According to Architectural Record’s ranking of the top ten undergraduate and graduate architecture schools, only one grad program, and zero undergrad programs, require a course in lighting design! So, at least in the U.S., we shouldn’t expect interior designers or architects to create more than utilitarian lighting because they’re not educated in the practice of lighting design.  Yes, many care quite capable of laying out a lighting plan that meets code requirements but we should remember that codes set minimum requirements for safety and energy efficiency. Codes have nothing to say about appropriateness for the application much less anything to do with aesthetics of the space or the interaction between light and materials.

So what do I tell my students? In the same way that there’s a difference between a decorator and an interior designer, there’s a difference between someone who can “do lighting” and a lighting designer. The differences are many, actually, and include academic education and training, continuing education, range and depth of experience, and a focus on the practice lighting design as a profession and a livelihood, not as an ancillary service. I tell them that it’s important for them to be able to speak the lighting designer’s language and to understand the interaction between light and materials because lighting can have such a strong effect on their work. I tell them that they may find themselves lighting some of their own projects and I hope my class prepares them for that. In the end I also tell them I’m sure they’ve learned that the best lighting designs are created by a professional lighting designer. If they want the best for their clients and their work, it’s worth the extra fee and worth talking to the client about what a lighting designer can do to support and enhance the project. Everyone needs a lighting designer, they just don’t know it.

CRI Inches Forward

The CIE’s Color Rendition Index (CRI) has long had several known weaknesses including outdated components of the calculations, a limited set of color samples, and standard reporting of only one piece of data (the average color distortion of the first eight colors, known as the General Color Rendering Index or Ra). After more than a decade of stalemate it seems that the IES’s TM-30 has convinced the CIE to make another attempt at updating CRI.

In a recently released position statement the CIE announced that the CRI technical committee (TC 1-90) has taken up the problem again and is expected to write a technical report on a new, improved color fidelity metric that can update CRI before the end of 2016. They will use TM-30 Rf as the basis for their work. Another committee, TC 1-91, will write a report on a color preference metric in the same time period.

This is both good and bad news. CRI is the international standard for measuring and reporting light source color rendering. It is long overdue for an update, and I’m glad to see the CIE working on it. On the downside, the press release makes it sound as though 1) parts of TM-30’s Rf may be incorporated, but the CRI fidelity metric will be a new creation 2) we may see the addition of a color preference metric but TM-30’s gamut metric Rg apparently isn’t being considered. The biggest reason that this is a concern is the amount of time it takes to create the work, gain internal consensus, approve the work, and gain organization approval – all of this before the work can be released to the larger lighting community for consideration. I think it is extremely optimistic to think that the two committees can write meaningful reports on these issues in only one year, especially given the difficulty they’ve had reaching consensus in the past.

I would much rather see the CIE committees study TM-30 and report on its strengths and weaknesses before deciding that it won’t work and they should start over. Adopting or modifying TM-30 can happen much quicker than developing one or more new metrics. TM-30 took three years to develop and the industry shouldn’t have to wait another three years for an updated metric that has the CIE’s approval.

This Is Not About Light

A Public Policy Polling (PPP) survey earlier this month revealed that an astonishing 32% of respondents supported making Christianity the official religion of the U.S., and that 14% were not sure. The political breakdown was as one might expect, with 42% of conservatives in favor, but 28% of moderates and 25% of liberals also in favor – of re-writing the First Amendment to the Constitution! This is not a blog about religion or politics, but I have to say something about the rising sentiment that the U.S. is, or was intended to be, a Christian country, or that it was founded on Biblical principles. Saying that the U.S. should have an official religion flies in the face of the First Amendment. It is both un-Constitutional and un-American.

Let me start by defining a few terms. A democracy is a form of government in which the supreme power is vested in the people and exercised directly by them or by their elected agents under a free electoral system.. A republic a state in which the supreme power rests in the body of citizens entitled to vote and is exercised by representatives chosen directly or indirectly by them.. A theocracy a form of government in which God or a deity is recognized as the supreme civil ruler, the God’s or deity’s laws being interpreted by the ecclesiastical authorities. So the U.S. is a democratic republic, with some issues decided by a popular vote and some issues decided by our elected representatives. Religious leaders do not decide issues because we are not a theocracy.

But, were we intended to be guided by religion? Was the government organized around biblical principals, as so many conservatives claim and desire? The surest way to answer that question would be to ask the founding fathers. Alas, they’ve all been dead for two centuries now but we don’t have to live in uncertainty. There are literally hundreds of thousands of pages of public and private documents that clearly detail their thoughts, desires, and intentions as they declared independence from Britain and created our curent form of government. We can end the bickering by simply looking at what they wrote. Now, I make no claims to being an historian, but I have long had a strong interest in U.S. history. I can say for certain that among the founding fathers Adams, Franklin, Hamilton, Jefferson, Madison, and Washington had no such plans for our country.

Did the founding fathers believe in God? In their own way, yes. Most of them were members of various Protestant sects. Benjamin Franklin was well known as a Quaker. Many were Deists, believing that while God created the world he does not interfere in it. But that doesn’t mean that they wanted a government based on religion. Let’s remember that one of the most significant reasons people emigrated to the colonies was to escape the state sanctioned religions of the European countries to be free to worship as their conscience dictated. This was still true in the late 1700’s, as the founders unquestionably knew. Establishing a state sanctioned religion under the new government was anathema to their experience.

The Declaration of Independence explains to the world why the colonies intended to separate themselves from Britain. The first two paragraphs provide a general explanation that is followed by a list of 27 items demonstrating the failure of the King to respect and protect the rights of the colonists. This is followed by two closing paragraphs. I think there are two important items here. The first is that there are mentions of, and appeals to, the “Laws of Nature and Nature’s God” “Creator” “Supreme Judge” and “Divine Providence” but no explicit mention of the Christian God. More importantly, none of the itemized complaints mentions God or the King’s failure to establish, implement, or enforce Biblical precepts. The colonies separated from Britain for secular, not religious, reasons.

The U.S. Constitution makes absolutely no mention of any god or higher power. The first ten amendments to the Constitution, the Bill Of Rights, were being circulated and advocated even before the Constitution was passed. In the First Amendment we find the only mention of religion, and that mention is part of a prohibition, “Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof…” which is known as the Establishment Clause.

The Federalist Papers were written by Alexander Hamilton (first Secretary of the Treasury), James Madison (fourth President of the United States), and John Jay (first Chief Justice of the Supreme Court) to convince the citizens of New York to vote in favor of the Constitution. They are one of the most cited documents in decisions issued by the Supreme Court. Not one of the 85 papers published between 1787 and 1788 discusses for the role of religion in the new government. In fact, they are silent on the subject because it simply wasn’t a consideration by those who drafted the Constitution or by those voting on it. The Anti-Federalist Papers are silent on religion for the same reason.

The Virginia Statue for Religious Freedom, written by Thomas Jefferson and passed by the Virginia General Assembly in 1786, clearly states that no one shall be compelled to worship or to support a church, and that establishing a church or requiring religious observances would be “an infringement” of “the natural rights of mankind.”

Finally, there were nine states with established (state sanctioned) churches in 1775. Between 1776 and 1778 five of those states disestablished their official religions, with the final state church (in Massachusetts) disestablished in 1833. So, not only did the founding fathers not intend for there to be a state religion, where a state religion existed as a carry over from the establishment of the colony that religion was disestablished and no religion was endorsed by the state.

I could go on but the clear point is that the founding fathers never intended for there to be a state sanctioned religion, and always intended for people to be free to worship as they saw fit with no interference from the government whatsoever. Anyone who claims otherwise is either ignorant of American history or willfully misrepresenting it. No one can legitimately claim to support the Constitution and an official religion because the prohibition against official religions is part of the Constitution. Of course, the Constitution is a living document and has been amended 17 times since the Bill of Rights. However, the idea of an official state religion not only runs counter to the foundations of the country but counter to the founding of the colonies. As much as one might cherish his or her religion, in the U.S. it is simply wrong to try to establish it over others.

LPDs, As Low As We Should Go

ASHRAE has released a series of changes to Standard 90.1 in preparation for the 2016 update.  Among those changes is the further tightening of LPDs (click here) in all space and building types.  In my opinion, these changes should be rejected by the lighting community.

Rather than provide tight, but reasonable, limitations on the power consumption of lighting systems, the LPDs proposed in the revision of Table 9.5.1 are so low that they clearly favor LED technology almost to the exclusion of all others.  They also strongly imply that energy efficiency is the most important criteria of a lighting system, regardless of the application.  Neither of these positions is appropriate for this document or the organizations that develop and maintain it.

The proposed LPDs are nearly impossible to meet by lighting designers who wish to exercise their best judgement, or meet client requirements, by selecting project appropriate sources of light other than LED.  In some cases this imposes an avoidable financial burden on the owner.  For example, LED luminaires with a combination of high output and smooth dimming to zero (such as those required for theatres, cinemas, houses of worship, etc.) are substantially more expensive than halogen alternatives, and may require more expensive control systems as well.  Clients requiring excellent color rendering (such as high end retail, art schools, museums, and health care facilities) are also compelled to purchase premium priced LED fixtures.

The only way that these low LPDs (and the even lower LPDs we assume will be proposed in the future) make sense is if they are paired with hours of usage to arrive at a time weighted limitations.  Even then, the LPDs should be high enough to permit designers and owners a choice in the technology that they use for a given application.  The proposed LPDs come very close to eliminating that choice.

I’m not saying that all buildings should be illuminated with incandescent light, or that LPDs should be abolished. I am saying, however, that the ever tightening of LPDs cannot go on forever, and that we have reached a tipping point where these limitations are having unjustifiable impacts on designs and budgets.  In my opinion, LPDs should not be further reduced for the foreseeable future.

Xicato Publishes IES TM-30-15 Results for its LED Modules

In a first (as far as I know) LED manufacturer Xicato has published TM-30 results for some of its modules alongside the CRI results for Ra and R9.  Menko de Roos, CEO of Xicato, says “At Xicato we are very supportive of TM-30-15 overall and recognize the need for an improved metric system along these two dimensions.”  You can read the full press release and find links to the results here.

I’m excited to see this greatly improved color rendering metric being used by a major manufacturer, and hope to see more manufacturers releasing TM-30 results soon.  If you still haven’t looked into TM-30 there is an increasing number of resources available to you.  TM-30 is available for purchase here. You can also view the recording of a webinar sponsored by the DOE and the IES and presented by two members of the IES Color Rendering Subcommittee, Michael Royer and Kevin Hauser.

Light and Health Webinar, September 30

Almost as if on cue, Philips Lighting is hosting a webinar on light and health presented by Mariana Figuerro, the Light and Health Program Director at Lighting Research Center.  I attended one of her in-person seminars earlier this year and I can say that she does a great job of explaining what aspects of light and health we can integrate into our practice now, and what aspects need additional research.  You can read more about the webinar here, or go straight to the registration page here.