Research Meetings
MERLIN Symposium
Night Vision - Lighting for Residential Roads
Thursday 30th June 2011
| Location | City University London (Tait Building) Applied Vision Research Centre Northampton Square, School of Community and Health Sciences London EC1V 0HB. View location map |
| Registration | Download booking form |
Symposium content
This one‐day symposium aims to explore current issues in street illumination with emphasis on mesopic enhancement of residential street lighting so as to better understand the needs of pedestrians and other street users and to formulate optimum research needs.
Who should attend?
The symposium will be of interest to anyone working in the lighting of public areas, to lighting manufacturers, to professionals working in visually demanding occupational environments as well as to lighting engineers, architects, optometrists and vision scientists. Support has been secured from leading lighting societies and the symposium will qualify for CPD.
Background
Mesopic vision is of relevance to lighting since it describes a range of light levels, often found in residential streets and other night lit environments, when signals generated in both rod and cone photoreceptors in the eye contribute to the visual response. Many changes occur in what has often been described as the "twilight" zone and these changes affect directly the performance of the visual system. Colour and spatial vision deteriorate as a consequence of the shift from cone to rod vision. The eye becomes more sensitive to shorter wavelength light but both visual acuity and the ability o to see faint objects worsen in the mesopic range. The spectral sensitivity of the eye changes and this has consequences for photometry.
At present there is no measure of luminance that reflects accurately the use of scotopic, photopic and colour signals in the mesopic range. Differences in the operational characteristics of rods and cones lead to changes in spatial and temporal resolution as well as absolute sensitivity to light and glare. Although the rod and cone systems are generally considered to operate independently, it is well known that in many lighting conditions visual performance is affected by the interaction of rod and cone signals which depends on light adaptation, stimulus size, spectral composition and more importantly, the location of the object of interest in the visual field.
Mesopic vision covers almost a thousand fold range of the lighting conditions one is involved with on a daily basis. The out‐door environment from twilight to dark in urban areas with streetlights falls in the mesopic range. In spite of its functional importance, the mesopic range is poorly understood and this makes it difficult to optimize lighting conditions to achieve energy efficiency without introducing unacceptable loss in visual performance. The need to save energy has prompted reevaluation of lighting needs with some local authorities considering switching off sections of lighting at night. Alternative solutions that can save energy without compromising the safety of street users at night must also be considered.
This symposium is timely and covers key issues in mesopic vision, the needs of pedestrians and vision related problems in street lighting conditions, as well as the practical implications of new lightingtechnologies. The symposium is being organised as part of the MERLIN project which aims to investigate how one can improve the lighting of residential streets by making optimum use of recent advances in our understanding of mesopic vision and lighting technologies.
The aim is to ensure that any important concerns / outcomes that emerge from the symposium are reflected in the work of the MERLIN project.
Mesopically Enhanced Road Lighting Improving Night Vision
Provisional Programme
| 9:30 to 10:00 | Registration / Coffee |
| 10:00 to 10:05 | Welcome |
| 10:05 to 10:20 | Introduction to Merlin |
| 10:20 to 11:00 | Review of mesopic vision |
| 11:00 to 11:30 | Review of research on light source SPD in street lighting |
| 11:30 to 12:00 | Discussion / Coffee break |
| 12:00 to 12:20 | Introduction to the needs of street users |
| 12:20 to 13:00 | Round table discussion |
| 13:00 to 14:00 | Lunch / Posters / Equipment exhibits |
| 14:00 to 14:30 | Current trends in street lighting |
| 14:30 to 15:00 | Light sources / new developments and implications |
| 15:00 to 15:30 | The impact of centrally managed lighting systems |
| 15:30 to 16:00 | Tea / Discussion / Posters / Exhibits |
| 16:00 to 16:30 | Review of recent studies in street lighting / questions |
| 16:30 to 17:00 | Forum on ongoing street lighting research |
| 17:00 to 17:30 | Discussion: residential street lighting, future directions |
| 18:00 to ‐ | Symposium dinner |
The symposium will be hosted by the Applied Vision Research Centre at City University London. Refreshments and lunch will be provided. An optional, evening symposium
dinner will also be organised.
For further information, please contact:
Simona Wade
Applied Vision Research Centre
The Henry Wellcome Laboratories for Vision Sciences
City University
Northampton Square
London EC1V 0HB
Tel: (020) 7040 8331
Intl: +44 20 7040 8331
Fax: (020) 7040 8355
Intl: +44 20 7040 8355
Symposium organisers:
John Barbur (City University London)
Steve Fotios (University of Sheffield)
Peter Raynham (University College London)