Re:Treat artificial light like other forms of pollution, say...
by wlesieutre on Wednesday November 04, 2020 @12:21PM
(#24991003)
Good point, but I read that as being more that 400W were going into the neighbor's window or up into the sky, and the 100W is intended to keep same light levels as before.
If you don't need those light levels, a 50W floodlight would cut the remaining light pollution from upward reflections in half.
Note that the little diagram also dims the light source from 500W to 100W. :)
In terms of candela, sure some light will always be reflected upwards but focusing on that really is a case of the perfect is the enemy of the good.