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nobody

15 Apr 2017 16:42



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A few years ago, I began hearing city observers complaining that their light-pollution filters just didn't work at all. According to these folks, not only did their OIIIs and Ultrablocks not improve nebulae, they actually made them look worse. I knew this wasn't true, as I've used these filters very successfully in the city with scopes as small as 60-mm.