Daystar ERF 150mm with 180mm Cap - E-180N150 Astrozap Specialty and galaxies

and galaxies

DayStar filter assemblies operate best at f/30 and slower

Celestron NexStar 5i/8i

Lumicon Sky Vector

If you already have one

Daystar ERF 150mm with 180mm Cap - E-180N150 Astrozap Specialty and galaxies150mm ERF Glass, Cell & 180mm ID Cap For Refractors DayStar Energy Rejection Filters reduce the heat load on your filter assembly by absorbing or reflecting UV and or I light and transmitting light in the desired visual spectrum. These filters are sometimes Red or Yellow glass, or dielectric IR and UV, but pass light in the desired visual spectrum. The ERF can also serve as an aperture mask to accomplish a straight angle of incidence for light