NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: EBBCO/filters
From: Ken Muldrew
Date: 2007 Nov 22, 10:10 -0700
From: Ken Muldrew
Date: 2007 Nov 22, 10:10 -0700
On 22 Nov 2007 at 2:27, Michael Daly wrote: > Given that a 4 1/2" x 5 1/4" glass shade is only $2.10 retail at the > local welding shop, I don't think that using a few one-square-inch > shades (at 10 cents per) on a sextant is particularly extravagant. In > polycarbonate, they run about 12 cents per sq. in., retail. Still cheap > and quite tough. It should be noted that glass welding shades are of apalling optical quality (at least every one that I've ever used has been very bad). The plastic ones give a nondistored image when you look through them, but one would be wise to check for any refraction when using them in a sextant. Ken Muldrew. --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---
