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: Greg Rudzinski
Date: 2009 Jul 5, 20:53 -0700
From: Greg Rudzinski
Date: 2009 Jul 5, 20:53 -0700
Douglas, You may be confusing my average index error (which is an arbitrary amount that I like to keep below a minute of arc by adjustment) with the standard deviation of my data sets. The SD of .15' and .28' for the scopes used is less than your .4'cone size. This might be because of the magnification. My naked eye observations should be disregarded because of my in ability to focus on a distant horizon properly.On a good vision day I should be able to do better with the sight tube. Greg On Jul 5, 3:31�pm,wrote: > With consideration of the last posting regarding retinal receptors and vernier acuity: > > I note the practical results of horizon index error measurement here by Mr. Rudzinski, and of the results in the paper by Gordon; and the results posted by others here, �amount to around 0.4 minute of arc to one minute of arc. > > The cone diameter is about 0.4 minute of arc. > > 'Normal' visual acuity (depending on the target type) is between 0.4 and one minute of arc. > > Curious coincincidence, do you not think? > > Douglas Denny. > Chichester. England. --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---