A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Ken Gebhart
Date: 2014 Oct 02, 14:30 -0500
Mind telling me where you got this sextant?
The sextant is a brand new Ogawa Seiki, clone or twin of a Tamaya. I have adjusted the index and side errors. Adjusted index error by shooting the sun with arm set at zero, made the two images coincident and read index error, 2' on arc. I take that off the double angle from the Art Hor siight. I reduce my sights using the HO 229 method, and check them with Navigator Light software. I am a little unclear on the Nav Light software, free version, as to how it handles A H shots. My shots have been lower limb, in other words, I bring the reflected image down and make it tangent with the top of the image in the horizon glass from the A H. I believe the software asusmes lower limb shots, and I enter half the angle. The software corrects for semi diameter.