Antlia 3nm H-Alpha Pro Series Filter - 31 mm - HA-PRO-3NM-31 iOptron iAFS Electronic Focuser a focal ratio of f/7

a focal ratio of f/7

The bundle includes a 4 lb counterweight and counterweight shaft

Includes a counterweight to counter-balance the telescope on this mount

Model C26AC Center-balanced Equatorial Mount from iOptron delivers precise pointing and accurate tracking

Antlia 3nm H-Alpha Pro Series Filter - 31 mm - HA-PRO-3NM-31 iOptron iAFS Electronic Focuser a focal ratio of f/7This very narrowband 3 nm H alpha 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. Important! Not for use when viewing or imaging the Sun! Antlia 3nm Pro Series H Alpha Filter 31 mm Unmounted This Antlia H alpha Pro narrowband filter optimizes the FWHM (full width half maximum) to a 3nm bandpass. As the bandwidth becomes narrower, the 3nm