SESSION 1: VISION
- Discomfort Glare: A Human Visual System model Malgorzata Perz & Gilles Vissenberg
- We will (briefly) review the current glare measures, revealing some of their shortcomings. Then, I’ll present the recent developments on the integrated discomfort glare measure based on the human visual system
- Lighting versus comfort Arnold Wilkins
- The human visual system evolved to process images from nature efficiently. These images have little rapid modulation in light level. The lighting chromaticity is close to the Planckian l focus. The Fourier amplitude is proportional to wavelength, i.e. to the reciprocal of spatial frequency. The color contrast is modest. I will consider how electric lighting is un-natural in all four respects and how it causes discomfort and cortical hyper-metabolism as a direct result. There are large individual differences in the perception of the rapid modulation of light but Individuals who experience visual stress can see temporal light artifact from flicker at frequencies up to 11kHz. Although healthy individuals find lighting comfortable when it has a chromaticity close to the Planckian locus, those who experience migraine with aura choose as comfortable strongly saturated colors of lighting, mostly well away from the Planckian locus. The spatial arrangement of ceiling luminaires is often such as to create an uncomfortable repetitive pattern of bright light sources. The properties of uncomfortable patterns are well described, and it is possible to use computer algorithms to avoid such uncomfortable arrangements.
- Making lighting research more credible Jim Uttley
- A range of scientific disciplines are currently undergoing a 'reproducibility crisis', which questions the credibility of much previous research. This talk will highlight some of the issues raised by the reproducibility crisis and their relevance to lighting research, and discuss opportunities for improving our research practices to ensure we gather and report meaningful and credible data.
04:05 Discomfort Glare: A Human Visual System model presented by Gilles Vissenberg
23:50 Lighting versus comfort presented by Arnold Wilkins
48:52 Making lighting research more credible presented by Jim Uttley
1:21:16 Q & A with all presenters
Gilles Vissenberg (born 1972, St. Maarten, Dutch West Indies) is principal scientist lighting applications at Signify Research, Eindhoven, The Netherlands. His current and previous work interests are optical design of LED lamps and luminaires, lighting application research, office lighting, energy saving and quality of light. He worked on LED spot lights and general illumination LED lighting systems, with a focus on low-glare solutions. He Dutch voting member of CIE division 3 (interior environment and lighting design) and was involved in the recent correction to the unified glare rating (CIE 232: 2019). He holds a Ph.D. from Leiden University, the Netherlands, and a Master degree in Theoretical Physics from the University of Nijmegen, the Netherlands. He published over 30 scientific papers and filed over 170 independent patent applications (88 patents are granted in the USA), mainly on illumination optics and LED lighting applications.
Małgorzata Perz was born in Poland in 1984. She goes by Gosia. She completed her secondary education at the Sports Championship High School in Szklarska Poręba, where she practiced biathlon. She studied Information and Communication Management at Neisse University and received her BS diploma in 2006. She continued her education at Wrocław University of Technology and in 2007 she earned Inzynier (Ir) degree in Computer Science and Management. Meanwhile, from 2006 to the end of 2007 she worked at Capgemini (PL), holding position of an Incident, Problem & Change Manager. In 2008, she moved to The Netherlands where she enrolled at Eindhoven University of Technology and followed Human-Technology Interaction program. In 2010 she received her MSc degree, following her diploma internship at Philips Research Europe. After graduation she worked at Philips Research and since 2016 she works at Signify Research, holding position of Scientist Optics Light & Vision. In her work she mainly focuses on studying different aspects of quality of light, including temporal, e.g. flicker, and the stroboscopic effect, spatial, e.g. glare and sparkle, and spectral, e.g. whiteness. From 2014 to 2019 she conducted research at TU/e Intelligent Lighting Institute, resulting in a thesis entitled Modelling Visibility of Temporal Light Artefacts for which she was awarded her PhD cum laude.
Arnold Wilkins is a Fellow of the British Psychological Society and an Honorary Fellow of the College of Optometrists. His postdoctoral study was undertaken at the Montreal Neurological Institute where he became interested in photosensitive epilepsy. He then spent 22 years at the Medical Research Council Applied Psychology Unit in Cambridge studying light sensitivity as it occurs not only in epilepsy, but migraine and dyslexia. In 1997 he moved to a chair at the University of Essex, where he is now Emeritus. He has published extensively on visual stress and authored three books.
Jim Uttley has a background in Psychology and Behavioural Science. His research applies principles of behavioural research and environmental psychology to the built environment. One of his main interests is the influence of the built environment, particularly lighting, on active travel.