NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Sextant and Eye Optics
From: Bill B
Date: 2006 Dec 06, 03:57 -0500
From: Bill B
Date: 2006 Dec 06, 03:57 -0500
Michael wrote > Then you take the sextant out in the dark when the > eye's focusing mechanism doesn't always have enough > power in the image to operate properly. Those of us > who use spectacles can test this by going out in the > middle of a dark night ( moon perhaps too full at the > moment ), wait for your eyes to adjust, then look at > the stars ( no instrument ) with and without the > specs. You will find that the specs don't make any > difference at all.... For me (for many reasons) I believe dark adapting is a poor choice for cel nav in most cases. If you have been reading the list for awhile, Frank Reed pointed us to an article in the September 2205 "Sky & Telescope." It was titled, "Optimizing Your Eyes for Astronomy." It dealt with night vision--among other topics--and adjusting an eyeglass prescription for night viewing. At the risk of again hitting the same nail with the same hammer (which is not even mine), I again recommend the article. Bill --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---
