astro.n-minus

Filter

Baader Planetarium S-II Ultra-Narrowband-Filter (4nm) – CMOS-optimized

Key specifications

Filter typeNarrowband
PassbandS-II
Bandwidth4 nm

About

A CMOS-optimized 4 nm FWHM S-II ultra-narrowband filter for systems slower than f/3.4, aimed at heavily light-polluted skies, with Reflex-Blocker hard coatings, sealed coating edges and blackened edges.