astro.n-minus

Filter

Astronomik UHC SC Rear Cell (2" / 24TPI)

Key specifications

Filter typeLight Pollution
Passband480-505nm + above 645nm
Bandwidth25 nm
Filter sizeOther
MountedYes

About

An Ultra High Contrast filter passing the OIII and H-beta lines at near 100% while blocking sodium and mercury street lighting and natural airglow, lifting gaseous and planetary nebulae out of the sky background. Usable from f/3 to f/15. This is the version that threads onto a Schmidt-Cassegrain rear cell.