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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Shade safety on Davis 15
From: Paul O
Date: 2026 Mar 26, 10:48 -0700
From: Paul O
Date: 2026 Mar 26, 10:48 -0700
Greetings - first time post here.
I had been doing my sextant sightings with my Davis 15, and another very experienced teacher tried them and immediately found the shades to be of unsuitable quality. Indeed my eyes were sore on my sightings.
Since then, I've found that I can screw in a telescope lens filter that is 1.25" diameter into the site tube of my Davis, or tape it to the 'sun' end of my 3x telescope site as well.
I have several that I can stack, and they each have what is called an 'ND' (neutral density) ratings of 4, 8, 16 and finally the darkest = 32.
I've not noticed any problems, and they seem to work quite well.
Although, the other day when I spent about 30 minutes practicing some artificial horizen readings at noon - I had a bit of a headache later that day. This could be totally unrelated, but I thought I'd drop you a line to get your thoughts if these ND filters, when used along with my sextant filters, should suffice for my eyes? I always have all the index filters down, plus 1 or 2 of the horizon shades.
Today, I took some solar eclipse viewing film and sandwiched that between two of the ND filters. It works, but the sun is VERY dark almost too dark to see. I bought those cardboard solar eclipse sunglasses for the eclipse a few year ago here in New England - they worked like a charm.
Thoughts from anyone? I see online for sale an ND 1000 filter, and I'm not sure if that is as dark as the eclipse film - it's short money so I may just try it.
Tks Paul
