Naomi Miller, Pacific Northwest National Laboratory | Michael Royer, Pacific Northwest National Laboratory
Wednesday
March 19, 2025
10:30 am - 11:30 am EST
March 19, 2025
10:30 am - 11:30 am EST
Credits TBD
Intermediate
You might see it at the Paris Opera House, or your favorite bistro, or your home bathroom, or the car driving toward you. Or, you may see no repeating patterns (i.e., the phantom array effect) from flickering lights at all. Therein lies the quandary: A chunk of observers see nothing; while others may experience headaches, migraines, disorientation, or worse from this flavor of temporal light modulation (“flicker”). In the effort to ensure energy-efficient lighting technologies also provide comfortable environments, PNNL completed an experiment comparing the sensitivity of migraineurs and non-migraineurs. There was a wide range of visibility to surprisingly high frequencies of modulation, as well as differences in sensitivity and in post-experiment outcomes between the groups. Beyond these experimental results, this presentation will discuss new data on the prevalence of flicker in schools, the forthcoming specification guidance in IES TM-39, and the new phantom array visibility metric. Whether you see flicker or not, come to learn why this is an increasing concern with LED systems and how it can be fixed.
Knowledge of basic lighting terminology, especially temporal light modulation is recommended.
Learning Objectives
- Comprehend why LED lighting systems are more prone to flicker than conventional sources.
- Be able to list potential health implications of temporal light modulation (headaches, nausea, migraine, disorientation, etc.)
- Experience what the stroboscopic effect looks like, as well as the phantom array effect. Articulate the four principal waveform characteristics contributing to flicker visibility and detection.
- Understand the three recommended metrics that apply to different frequency ranges, and target values for these ranges in different applications and for different populations.
Speakers
Naomi Miller
Senior Scientist
Pacific Northwest National Laboratory
Naomi Miller straddles the line between design and engineering at the Pacific Northwest National Laboratory in Portland OR. As a senior scientist she applies her decades of experience in architectural lighting design in Upstate New York and San Francisco to nudge design professionals, product manufacturers, governments, and end users towards more visually uplifting, environmentally-responsible, and healthy lighting solutions. She researches and reports on lighting quality issues such as visual comfort, flicker, and light distribution with respect to solid-state products. Lighting is an intriguing stew of economics, human factors, and physics; an essential element of productivity and comfort; and a necessary element of visual delight. In 2023 she received the CIE Waldram Gold Pin for Outstanding Contributions in Applied Illuminating Engineering, and in 2024 received the IES Medal Award. She is both a Fellow of the Illuminating Engineering Society and the International Association of Lighting Designers.
Michael Royer, Ph.D.
Human Factors Engineer
Pacific Northwest National Laboratory
Dr. Michael Royer joined PNNL in 2011 and primarily works on the Advanced Lighting Science and Technology Research program, with an emphasis on human factors. He conducts experiments to help refine metrics and specification guidance, with the ultimate goals of advancing lighting quality to improve building occupants' satisfaction and increasing the use of energy efficient lighting technologies. He has been instrumental to the development of ANSI/IES TM-30-20, IES Method for Evaluating Light Source Color Rendition. He has authored over 70 journal articles and government reports covering many aspects of light and its application in architectural environments.
Michael is chair of the Illuminating Engineering Society (IES) Vision Science committee and a member of the IES Color Committee. He is an associate editor for the journal Lighting Research & Technology. He has a joint appointment as Courtesy Faculty at Oregon State University.
Prior to joining PNNL, Michael earned a Ph.D. in Architectural Engineering from Penn State University, receiving the 2013 Taylor Technical Talent Award from the IES for his published work, which focused on tuning optical radiation for visual and nonvisual effects.