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DARK SKIES,PERCEPTION OF SAFETY AND AESTHETICS. Peter McLean Lighting, Art + Science. External Illumination is a byproduct, possibly a necessity of the developed world. What is the purpose of external lighting?. Work longer. Extend working hours beyond daylight. Play longer.
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DARK SKIES,PERCEPTION OF SAFETY AND AESTHETICS Peter McLean Lighting, Art + Science
External Illumination is a byproduct, possibly a necessity of the developed world
Work longer Extend working hours beyond daylight
Play longer Extend leisure activities beyond daylight hours
Night Sport • Spectator Sport • Sports training • Extension of day activities • Football – Golf - Hockey
Safe Movement • Negotiate and navigate outside at night • Streetlighting • Car Headlights • Pedestrian Lighting
Establishing a night presence Creating high visual impact advertising Advertising
Night Aesthetic Environment • Buildings • Landscape • Artwork, fountains, monuments, bridges, natural formations
Safety and Security • Reduce the Risk of Accident • Reduce the Risk of Crime • Increase the Perception of Safety
Why is there a need to control sky glow? • Not purely sky glow that needs to be controlled but the general waste and unnecessary lighting
Why is there a need to control sky glow? • Astronomy – professional and amateur • See the night sky – not just a few stars • Preserve darkness as part of the environment
Opinions • Interests • Vested interests • Knowledge or ignorance • Priorities
Advocates for both sides see themselves as being in the right • Concessions and Compromise • Can it go far enough to be useful in the long term? • Is it like King Canute stopping the tide?
New risks to the skies • Lighting as a tool for Crime Prevention • Liability and the risk of litigation • Pseudo Standards and minimum illuminance levels
“On average, 40 per cent of night time street crime occurs when lighting levels are at five lux or below ( a lux is a measure of lighting : a typical side street has a level of about two lux at night and 18,000lux on a bright day). Only three percent of crime at night occurs when the lighting level is above 20 lux”ACT Crime Prevention & Urban Design Resources Manual quoting, Paul Stollard, Crime Prevention through Housing Design, London, Chapman and Hall 1991.
“electricity is the high priest of `false security”Sherlock Holmes Increased public lighting has become the high priest of crime prevention
Minimum and Uniformity determine Average • Uniformity = Min/Avg • Avg 7 , Min 2 Uniformity 0.29 • Avg 20 , Min 10 Uniformity 0.5 • If Min fixed at 10 and the best uniformity that can be achieved is 0.3 • Avg = 33
Vertical Illuminance • Excessive levels and coverage means it becomes the primary design criteria • Pushes designers away from cut off fittings • Increases glare and upward light output
End Result • Illumination levels are being forced up by people deciding that they want “better than the code” • Raising minimum levels is further forcing up average levels • Vertical illuminance requirements are increasing the upward light output
End Results • Justification is safety and security • Fear of litigation stops rational evaluation
End Results • Justification is safety and security • Fear of litigation stops rational evaluation
End Results • Justification is safety and security • Fear of litigation stops rational evaluation
End Results • Justification is safety and security • Fear of litigation stops rational evaluation
End Results • Justification is safety and security • Fear of litigation stops rational evaluation