Light quality should drive LED and SSL sector successes (MAGAZINE)

Oct. 21, 2021
The comprehensive Strategies in Light program touched all angles of the LED and solid-state lighting technology sectors, and MAURY WRIGHT reports that the key messages resounded around light quality.

Strategies in Light 2021 took place in a virtual conference venue on Aug. 24 and 25, but don’t let the online setting deceive — the presentations were excellent. Moreover, there were virtual networking opportunities, video interviews, online product demonstrations, and more in addition to the two days of presentations. You would struggle to find an angle of the LED and solid-state lighting (SSL) sectors not covered in the program, including connected lighting, smart buildings, additive manufacturing, germicidal ultraviolet (GUV), and more. Here we will focus on the keynote from a lighting designer at the top of the profession, and a session on lighting for health and wellbeing. The recurring theme is that light quality — indeed beauty and aesthetics — are the elements that can drive our industry forward.

Strategies in Light was originally scheduled as an in-person event in its normal February slot, was postponed due to the pandemic and still planned as an in person event, then was ultimately forced to the virtual setting by COVID-19. Ironically, it was Strategies in Light 2020 in San Diego when many of us last gathered at an in-person event. And COVID had even impacted attendance in San Diego.

Still, the 2021 event was an outstanding learning opportunity as you will glean from the presentations discussed here. And also realize that the online format means you can still catch the archives on demand for a limited time. The keynote address came from Jim Collin (Fig. 1), who is partner and head of sales for architectural lighting at Swedish firm Annell Ljus + Form AB. Collin came to fame as an engineer turned lighting designer who rose to the position of international head of Light Bureau with more than 100 lighting designers reporting to him.

Light and impact

Collin set the tone for his keynote with an observation set in the historic Pantheon church in Rome where he said that daylight is the only form of light that reveals the iconic architecture and historic works, and he presented some images captured in full daylight (Fig. 2). That example set the scene to discuss the fantastic light produced by the sun but also to point out the impact of time of day and season. Next, he showed summer images from his Swedish cabin starting with a 4:00 AM image and noting that during summer the light was essentially the same at 3:00 PM or 10:00 PM.

Collin went on to show a series of photos of both artificial light sources such as fire, candle, and electrical, and indoor and outdoor images illustrating lighting effects. He ended with a photo of the Vessel public complex of intertwined stairways located at Hudson Yards in New York. Referring to the series of photos, Collin said, “That’s one year of my life as presented to me by my iPhone.”

He pointed out that the audience might miss the relevance of the year-in-life presentation relative to the lighting industry, so he explained the tie. Collin said, “This is a technology that understood early the importance of implementing beauty and aesthetics. It’s a technology that understood that user experience is absolutely vital — an early adopter of artificial intelligence allowing me as I’m sorry to say, a most mediocre photographer to take quite decent pictures.”

Collin gave a brief bit of background using a tongue-in-cheek strategy to point out career successes despite describing himself as “not being brilliant in technology or aesthetics. Thus I was forced to be skilled in both fields and master the lands in between where all artificial lighting is born.” He said his goal with the presentation was to offer the audience insight into that borderland where the lighting design profession has a great future. He said technology would be the key driver while aesthetics would be the key enabler.

Magic of light

Collin is an engineer turned lighting designer, and he describe his early days in lighting as being a “true foot candle counter.” He said his only problem was that he kept meeting “weirdos” who created obstacles. He acknowledged that they didn’t call themselves weirdos but rather architects, and that they kept questioning him on engineering-centric decisions such as why a room needed 17 luminaires rather than 16. He soon realized that he was the oddball after continuing to meet said weirdos, so he returned to school to study aesthetics and light. He emerged with an appreciation for the brilliance, importance, and magic of light.

He also said he came to the realization that simply knowing about the magic was not enough. He felt he had to prove it to other people. So he devised a thought experiment that lets you feel the magic of light. Collin asked the audience to close their eyes and imagine themselves on a pristine beach lying in a hammock under palm trees at some faraway paradise. He suggested that people told to imagine such a setting automatically imagine fantastic natural light and a clear sky. A person would not imagine, say, a stormy day with overcast sky and low light levels. He said the experiment proves the magic of light.

Collin said it’s “not the fact that light has great impact on our food patterns, our sleep patterns, and our date cycle.” Rather, the magic is that light can change our emotional state with the blink of an eye. The point he was making is complex and, to a point, counterintuitive. The overcast beach image he showed might ruin the pleasant thoughts that the audience had of a sunny day. Yet he said the natural light on the overcast day was perfect light. It was completely glare free and uniform. But perfect light characterized by meeting standards or codes has nothing to do with good light, was Collin’s point.

Collin said the problem we face is that we tend to look at light as something that is easily measurable. “We should think of light as something that is always perceived and deceived by the human brain,” said Collin. The human brain yields an immediate response to light of an object or surface but perhaps not a correct interpretation. An example of a chessboard-like image made the point that light could alter the brain’s perception of color shades.

Moving to lighting design

Collin then transitioned the thought process to the typical office space or educational classroom and the problem with specification by simple metrics. He identified the ubiquitous troffer as an issue, saying that troffers offer perfectly uniform glare but are used because of ease of installation and costs. Collin said much of our global population works or studies under a dull gray haze and at the same time leaves the supply chain and lighting manufacturers dealing with “appallingly-low profit margins.” He lamented that the industry has attempted to make troffers work broadly in applications going back to the 1950s and 1960s and even today. “This is a perfect example of short-sighted stupidity,” said Collin.

The more recent culprit Collin targeted is the planar diffuse luminaire that emerged as a way to try and harness bright LED point sources. Some such minimalist luminaires were quite good, but the lighting industry has moved to slash prices and copy intellectual property. “Can you imagine anything more easy to copy than a flat square panel?” Collin asked ironically. Some manufacturers added features that could slow the copycats, according to Collin. But he said features such as tunability for human-centric lighting have been driven not by need but by manufacturers needing to sell products.

Collin predicted that manufacturers and other supply chain participants that focus on planar troffers would be going out of business down the road. Moreover, he said the products are arguably dangerous because they provide too much light. And people in a space need a mix of directional and ambient sources that can deliver better vertical illumination.

Of course, there are lighting designers/specifiers who are supporting the continued dominance of the troffer. Collin suggested most are ignorant of the needs of people working in a space. And quite often choices are being made by an engineer or technician who is not trained in light science. He said anyone specifying lighting needs to put user experience first. “We need to make sure that tech guys think about beauty,” said Collin. Also, artists need to think about technology. “Cooperation and broad thinking is the key,” said Collin. “Merging these two worlds together holds that key.”

Back to incandescent

To illustrate his points, Collin referenced a project he worked on in 2013. A newly-built office had state-of-the-art building systems for occupancy comfort including air-quality systems. The space was lit with modern fluorescents but was overlit and not comfortable. Collin was able to convert the space using incandescent technology based on a promised 80% energy savings providing light just where it was needed. Moreover, he termed it perfect light for the workers.

One of the key features in the project was end-user control of lighting at each desk. Collin said such control is eschewed by management in some cases but should be mandatory. He said, “It’s a human right to be able to turn off your own light.” The project delivered 92% efficiency. “All we did was use the opposite of ignorance,” said Collin. “We used common sense and knowledge of the user experience.”

Moving toward the close of his keynote, Collin discussed other factors impacting the lighting industry. He said like it or not, digital was coming to lighting and the lighting industry should encourage the evolution while trying to use the knowledge of lighting and human perception to set the tone of the evolution. And Collin said the Internet of Things (IoT) movement that has been slow to take off in lighting will happen, it’s just a matter of time. The data that’s accessible in buildings is just too valuable and lighting is the natural middleman.

Lighting for health and wellbeing

Several times during the keynote, Collin mentioned human-centric lighting but mostly in a negative fashion, citing many such products as not based on industry need. It turned out that the Strategies in Light session on lighting for health had some parallel elements to it. Perhaps it’s time to rethink the concept and the desired results.

Having served up something of a disclaimer about research and real life, Houser turned to discuss how the light-centric variables impact health. He said temporal or time patterns are the most significant stimulus. That’s not true of the vision systems but for the circadian system. Intensity is second in impact of stimulus and spectrum third, but in both cases you need a logarithmic change in stimulus to impact a linear response for instance, in melatonin suppression. Houser made what is a very complex topic seem simpler and said a healthy prescription for day-active people is high-biological-potency lighting morning through end of the workday, mid-potency lighting through early evening, and low-potency lighting at night.

Houser did raise an interesting logistics question asking, “Who is responsible for providing health-oriented lighting solutions?” He wondered if individuals should be responsible for making sure they get the right dose of light or if that should be incumbent on a building owner or, say, a school district. And he made one very interesting point. For day-active people, the place they live and sleep needs lighting with three potency levels. But work or educational spaces really only need the high-potency setting. He does not believe the systems that change levels or spectrum during the work or school day are needed or effective.

How LEDs come to play

Following Houser, Robert Soler (Fig. 5), co-founder and vice president of biological research and technology at BIOS Lighting, took the microphone to discuss LED technology that enables lighting for health applications. We’ve written previously about BIOS’ research that located peak circadian sensitivity at around the 490-nm wavelength. Moreover, earlier this year, BIOS and Lumileds announced commercial availability of an LED with a 490-nm blue peak for enhanced stimulus of the circadian system.

In his Strategies in Light presentation, Soler leaned toward promoting BIOS technology but still delivered some very informative points. As many of our readers know, we have devoted considerable pages to the topic of circadian response in the past few years. We published a four-part series by the Lighting Research Center at Rensselaer Polytechnic Institute before the authors moved to the new Mount Sinai Light and Health Research Center. And we published an article by Circadian ZircLight on the topic.

The various recent research generally supports the theory of circadian peak sensitivity above 450 nm where most white LEDs have a blue peak. What Soler did in his presentation was take a detailed look at the phosphor mix required to deliver a 4000K CCT light using pumps that ranged from 410500 nm. You should catch the archive if you want to understand how specific CCTs are generated with blue pumps and phosphor.

The foundation Soler laid in the color-mixing explanation allowed him to present data that indicates the 490-nm-based LEDs deliver more circadian potency based on the color mix of the phosphor, than do 470- or 480-nm LEDs even if the circadian sensitivity peak is ultimately determined to be at 470 or 480 nm. It may have been a self-serving conclusion, but the reasoning seemed right.

Looking forward, you can say the presentations discussed here make a strong case for high-quality and high-circadian potency lighting as standard fare in office, school, and similar settings. We have mentioned the positive impact that quality has a number of times in the past few years, and really the lighting for health angle should be integrated in that discussion. That prescription would be good medicine for an industry seeking to escape the grip of a pandemic.

LEDs Magazine chief editor MAURY WRIGHT is an electronics engineer turned technology journalist, who has focused specifically on the LED & Lighting industry for the past decade.