Comments by "R" (@rdrrr) on "The High Pressure Sodium Light: Ubiquitous, effective, but good?" video.

  1. One of the major ones is around observatories. LPS lights have a much narrower frequency band than HPS lights, so it's easier to filter out the light they cast. I don't know if they're still commonplace in that context. Might be obsolete now LED lighting is commonplace; because LED lighting is much more directional, LED light fixtures won't cast so much light into the sky.
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