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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Sextant Collimation Error
From: David Pike
Date: 2020 Jun 25, 09:34 -0700
From: David Pike
Date: 2020 Jun 25, 09:34 -0700
Greg Do you know how big that collimation error is when using a ghost ring and not looking through it straight? Bill Bill. I wondered about this, because 6th Form Physics says that a marine sextant ought to be tilt proof in the fore and aft direction. Newton says the measured angle must be twice the angle between the mirrors; full stop. However, we rock the sextant to find the vertical. Perhaps a better place to begin an analysis ought to be looking at a plan view of the situation. Might there be a similarity between looking from the left of ring to right of horizon mirror as opposed to looking down the centre of and not holding the sextant vertical? I’m off to try it. DaveP
