Light Pollution CLS Filter 2"
Light Pollution Filter CLS for deep sky work
This filter passes light in the ranges for OIII and H-beta which allows excellent views and eliminates much artificial light pollution. It is similar to the UHC filter, but passes a wider band, transmitting more light.
90% transmission of main nebula emission lines (i.e. Ha 656nm, OIII 496nm & 500nm, SII 672nm and H-beta 486nm)
0.1% transmission of off-band, specifically the major emission lines of artificial light pollution (i.e. Na 589nm, Hg 435nm and 578nm).
This is threaded for 2" eyepieces.