NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: "Vernier acuity" of horizon IC tests
From: Douglas Denny
Date: 2009 Jul 7, 00:31 -0700
From: Douglas Denny
Date: 2009 Jul 7, 00:31 -0700
I am aware of the effect of magnification of telescopes. I confirm what you wrote about the Snellen chart and moving away to 140 feet is correct. What interests me, however, is that the x 7 telescope does not significantly raise the accuracy of celestial sights in the same ratio as the magnification of the telescope as one might expect by your experiment alluded to above. Without telescope can give around one minute of arc accuracy; with x 7 telescope can only improve that to around say 0.4 minute of arc. Douglas Denny. --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---
