Antlia 3nm SII Pro Series Filter - 31 mm - SII-PRO-3NM-31 finderscope The optics

The optics

This Prism is multicoated and built in a solid metal body

As much as we plan our observing or imaging sessions for perfect weather

About the Antares 6mm W70 Eyepiece - 1

or want to mount an Explore finder on another telescope brand

Antlia 3nm SII Pro Series Filter - 31 mm - SII-PRO-3NM-31 finderscope The opticsThis very narrowband 3 nm SII filter from Antlia is part of their Pro series and is of the 31 mm unmounted variety. It is normally used in a 1. 25" 31mm filter wheel, where it drops into place. Antlia 3nm Pro Series Sulfur II Filter 31 mm Unmounted This Antlia SII Pro narrowband filter optimizes the FWHM (full width half maximum) to a 3nm bandpass. As the bandwidth becomes narrower, the 3nm Pro narrowband filters enhance contrast of emission targets