astro.n-minus

Filter

Astronomik OIII 6nm 36mm

Key specifications

Filter typeNarrowband
PassbandOIII 496 + 501nm
Bandwidth6 nm
Filter size36mm

About

A 6 nm narrowband filter isolating the doubly-ionised oxygen lines at 496 and 501 nm, blocking sodium and mercury street lighting, airglow and most moonlight. The 6 nm width suits faint objects in crowded Milky Way fields, low dark-current cameras and heavily light-polluted sites. MFR coating, 36 mm round with a protective ring.