Quote:
Originally Posted by ausastronomer
Hi Joe,
Yes that's a "BroadBand" Light Pollution Filter. It doesn't need to be that one specifically, they all work very well as "Planetary Filters", notwithstanding they might not work as well as each other for their designed light pollution reduction purpose.
These work well as "Planetary Filters" because they reduce "Irradiation" which is the distortion of the Boundaries between light and darker features and they soften the tones of similar adjacent colours. Both of which helps to improve the "signal to noise ratio"
Cheers,
John B
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Yes John "IRRADIATION" is a problem most never recognize!
Cheers Bigjoe.