Today's Californian covers the Riverside County Board of Supervisors review of light trespass, brought before the Board by Supervisor Tavaglione (http://www.nctimes.com/news/local/swcounty/article_9b21982f-eb68-506a-b736-428477b26114.html).
The article reports Supervisor Ashley saying that
"most commercial properties before the board in the last decade or two have been vetted to ensure they are dark-skies friendly and 'There's probably not a lot more they can do unless they turn the lights out'."
Ashley reveals some misunderstanding of lighting and light trespass. Set aside for the moment that the County has allowed numerous violations of the lighting ordinance on commerical properties, light trespass refers to bad aim, and there is a simple solution.
Consider this photo of an arc around the sun. Notice how the photographer (me) is using the object in the foreground as a shield to block the bright direct light of the sun. I'm not advocating turning off the sun, but shielding it so I can see and take the photograph.
Now observe these lights. The top one is typical light installed by a developer, and shines more light on the neighbor's house than it shines on the property on which it's installed. This is bad design, wasteful use of energy, and light trespass.
The bottom photo is a properly shielded light, and everyone can see (and sleep) better.
Light trespass regulation isn't about denying anyone the right to light their property; rather, it requires that they do just that, light their own property.
The real advantage of a light trespass standard is that developers will stop installing lights that will be subject to a legal complaint. Instead, they should use lights with reflective hoods that aim all the light onto the property the light is intended to illuminate. By using all the light, the property owner will get effective lighting with a lower watt bulb.
Update 20 Oct 10. The Board voted 5-0 in favor: