If anyone here has ever been to San Diego, CA you will notice all exterior lighting, both street and private property, is done with low pressure sodium lamps and downward facing lights with shields. This is due to the Palomar Observatory. There are bands laid out around this place with lighting requirements specific to each. The further out the band the less stringent the requirements. I just did a job that fell under one of the less stringent areas but it is about 100 miles away from the observatory as a crow flies.
