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Re: Accuracy: main shades vs eyepiece shades?
From: Greg Rudzinski
Date: 2019 Jul 25, 07:56 -0700
From: Greg Rudzinski
Date: 2019 Jul 25, 07:56 -0700
Tony,
I haven't found a noticeable difference with Sun observations using different shade combinations or no shades when using the Davis artificial horizon. I'm sure there is some extra refraction but not enough to worry about on a high quality metal sextant. It would be better to focus on keeping observations in the center of the field of view and rocking the arc correctly to insure perpendicularity. Bowditch referes to shade error as a prismatic error (see page 411 in 1966 edition).
Greg Rudzinski
