A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Tony Oz
Date: 2019 Dec 8, 09:53 -0800
The ongoing discussion of the star-to-star angle as the sextant sanity check has reminded me my efforts to eliminate the IE (and side error too).
For me it is not so easy - even with the 7x (Keplerian) scope - to tell if both images of a star coincide perfectly. I have to move the index arm slightly to see where each image is.
Last time I did the adjustments I asked a friend to move his palm infront the horizon and index mirrors thus blocking temporarily either of the view paths. With the images (alternatively) blinking I can see the [non]coincidence much more clearly. I think some sort of fan propeller could be used as an obturator. Will try next time I take my sextants to the shore.