It’s time for the back to school music video about (sort of) light. So here’s The Doors on a set made of Doors(!) singing Light My Fire. Is that Andy Kaufman in the background?
Unfortunately, either GoDaddy or WordPress has done something dumb and I can’t insert a video. Go here now!
The IES is about to release an update to TM-30 (TM-30–18). Along with the updated version they have released this Position Statement.
Source: PS-11-18: IES Position on TM-30-18, IES Method for Evaluating Light Source Color Rendition | IES
This week I’ll be focusing and setting light levels in a new corporate board room. The first photo below shows testing of the RGBW LED cove lights. The second photo shows the partial installation of a hard dropped ceiling with downlights and a central luminous panel.
Sometimes the New York Times is oblivious and yesterday was one of them. In an article titled Lighting a Room, Simplified the author wrote about the importance of lighting in the home. In preparing the article, she spoke to and quoted four interior designers, one fixture manufacturers and one professional lighting designer. In addition, all eight of the photos in the article are taken during the day, so they’re nice illustrations of the use of windows and daylight in residential interiors but terrible illustrations of electric lighting, which is the topic of the article. They seem to be marketing photos for particular lighting fixtures, not examples of good lighting.
It’s too bad. There are plenty of lighting designers who would have gladly shared their expertise and their work with the public if asked. Unfortunately, this article is a reflection of the public’s (and the author’s) lack of awareness of the contribution good lighting, and therefore a good lighting designer, can make to a residential of commercial project.
Lighting doesn’t just come with a building. Most interior designers and architect receive little or no training or education in lighting design when they’re in school. Yes, some do have an affinity for lighting and can create beautiful work despite their lack of training. However, the best lighting design is most likely to come from the best trained people – professional lighting designers. If you are looking, one place to start is the IALD’s web site and the Find A Lighting Designer tool on the home page.
For many years the IES Ready Reference was on the desk of every lighting designer, and we were all baffled when they stopped publishing it. Great news, it’s back! This time as an app for your phone or tablet that’s available in the Apple App Store and Google Play. According to the IES, the app provides:
Download it from the Apple App Store or Google Play.
This semester’s back to school music video
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An architect recently emailed me asking if it was possible to use TM-30 metrics with daylight. My short answer was something like, “I suppose you could, but why would you?”
The long answer is that all of the TM-30 measurements (Rf, Rg, the 16 chroma shifts, the 16 hue shifts) are relative – comparing the light source in question with the reference light source. With daylight, you’d be comparing the daylight SPD you captured at a moment in time with the CIE definition of daylight at the same CCT. On an average day I doubt that any of the measurements would deviate from 100 by more than a couple of points. So, using TM-30 (or CRI Ra) is like measuring a ruler with another ruler. You’re essentially comparing one thing to a definition of itself.
By now most of us have attended one or more seminars or webinars about IES TM-30 and understand that it is a method of measuring various color rendering properties of a light source and reporting those measurements. The thing that’s been missing is a recommended set of values that set minimums, maximums and/or tolerances for the various measurements. This has been true for two reasons. First, TM-30 is a method and as such was never intended to set recommended values. The second is that while the science behind TM-30 is solid, the science doesn’t offer any predictions of acceptability.
Good news! After almost three years of research and tests around the world we’re much closer to establishing a set of recommended values. At this year’s IES Annual Conference in Boston, Tony Esposito, Kevin Houser, Michael Royer and I will be presenting the seminar “Specifying Color Quality With TM-30” The description of the seminar is, “This presentation will discuss several research projects which have used the IES TM-30 color rendition framework, and whose results have been used to develop various specification criteria. We will discuss UFC 4-510-01, The Department of Defense Unified Facilities Criteria for Military Medical Facilities, which has already implemented IES TM-30-15 specification criteria.”
During the seminar we’ll review some TM-30 basics, look at several research projects that are helping to establish TM-30 thresholds, and review how to use the TM-30 calculator. Don’t miss it!
Today, May 16th, is the International Day of Light 2018. It began in 2015 when the U.N. declared The International Year of Light and Light-based Technologies. Today, the International Day of Light is
a global initiative that provides an annual focal point for the continued appreciation of light and the role it plays in science, culture and art, education, and sustainable development, and in fields as diverse as medicine, communications, and energy. The broad theme of light will allow many different sectors of society worldwide to participate in activities that demonstrates how science, technology, art and culture can help achieve the goals of UNESCO – education, equality, and peace.
There are events around the globe related to the theme of light. If you’re interested you can check the web site, and the sites of organizations such as IALD and IES.
We’ve all heard about the effect blue light can have on our circadian rhythms. It can suppress the release of melatonin, which can delay sleep and reduce sleep quality with possible long-term health consequences. Circadian disruption has been associated with depression and increased risk of diseases such as diabetes, obesity and cancer.
Back in 2016 the AMA released a report recommending night-time outdoor lighting have a color temperature no higher than 3000 K to limit night-time exposure to blue light. That report was quickly criticized by the Lighting Research Center and the IES, among others, as I noted here and here. One of the key criticisms was that correlated color temperature is a poor measure of spectral content and says nothing about the amount of energy in the wavelength range that affects our circadian rhythms. A better measurement is melanopic content, which isn’t discussed in the report.
Last year Apple unveiled a feature in their OS and iOS called Night Shift. When enabled it causes the color of the display to become warmer in the evening. The assumption, the same as the AMA’s, is that warmer light has less blue so it won’t impact melatonin production.
A recently published paper in Lighting Research & Technology looked at the effectiveness of Night Shift. This preliminary study suggests that “changing the spectral composition of self-luminous displays without changing their brightness settings may be insufficient for preventing impacts on melatonin suppression.” Even when Night Shift was used, the devices still suppressed melatonin production. The authors noted that, “it is not known how this amount of suppression induces circadian disruption, delays sleep or affects health. Larger, more comprehensive epidemiological studies should investigate how the long-term use of these self-luminous displays affects people, especially adolescents and children.”
While additional studies are clearly needed, it provides additional evidence that lower CCT alone is probably not enough. With our display devices we should also lower the brightness.