HomeMy WebLinkAboutA015 - Letter from David Oesper supporting community-wide lighting intensity standard R
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It has been suggested that lighting intensity standards should be applied to
the entire community, not just the Northeast Gateway area. I completely
support enacting a community-wide lighting intensity standard.
However, because the Northeast Gateway area is likely to be a large-scale
development directly south of the McFarland Park Observatory, a lighting
intensity standard should be applied there first.
The purpose of lighting at night in commercial areas is to provide adequate
visibility, safety, and security for employees and customers. Neither the
retail industry nor developers should be dictating acceptable light levels.
The question "How much light is enough?" can only be adequately answered
by professional lighting engineers who understand both lighting technology
and the physiology of human vision. Such an organization exists: it is called
the Illuminating Engineering Society of North America (IESNA).
Light levels in commercial areas have been creeping upward over the past
few years, and there is absolutely no engineering or physiological
justification for these higher light levels. When I get out of my car in the
parking at Best Buy or Target at night, I find myself having to squint as I
walk towards the store. Such high light levels may be effective advertising,
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but they are not needed for safety, security, or good vision.
lumens per acre
100W incandescent = 1710 lumens
70W HPS residential streetlight = 63001umens
1000W metal halide parking lot light = 110,000 lumens
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Basic Enhanced Security With good lighting
design
Minimum 0.2 fc 0.5 fc these illumination levels
Maximum 4.0 fc 7.5 fc will be exceeded even at
Average 1.0 fc 2.5 fc 100,0001umens per acre
footcandle = 1 lm / ft2
Too often the world runs on perceptions rather than reality, opinions rather
than facts. Since lighting is for humans to see, let's base our lighting
decisions on the facts of human vision.
Too much light costs money, wastes energy, creates glare, makes
neighboring areas look too dark, and pollutes the night sky, an important
part of our natural heritage. The right amount of light facilitates good
vision, safety, and security in a way that is aesthetically pleasing and
complements nature instead of bludgeoning it. Ames is more like Flagstaff,
Arizona or Boulder, Colorado than it is like Las Vegas or Ankeny. The
decisions we make today will affect the quality of life in Ames for decades
to come. Please don't ever forget that.
David Oesper
1208 Wilson Ave.
Ames, Iowa