astro.n-minus

Filter

Astronomik OIII visual T-Mount (M42x0.75)

Key specifications

Filter typeNarrowband
PassbandOIII 494-506nm
Bandwidth12 nm
Filter sizeOther
MountedYes

About

A visual OIII filter with a narrow 12 nm window over both oxygen lines, blocking sodium and mercury street lighting and airglow for a large contrast gain on gaseous and planetary nebulae and faint supernova remnants. Suits f/3.5 to f/15 and apertures from 6" up. This is the T-mount (M42×0.75) version.