NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Brad Morris
Date: 2013 Aug 21, 12:51 -0400
Hello George
I'll be the 'master of the obvious". One of the prisms is rotated relative to the optical path. This is based upon "askew", meaning twisted relative to frame of reference. Which prism is rotated? Couldn't tell you.
Master of the Obvious.... Out
Hello all,
I have a Davidson optronics autocollimator with a strange quirk. I called Davidson and asked if they could calibrate it. They declined and stated this autocollimator could not be calibrated.
This model has a lit grid screen that sits askew in the field of view. (Google askew, I assume that is a Google joke.) The first mirror the light path hits is adjustable. The adjustment is similar to the three screw Dobson main mirror adjustment. It then hits a prism with a lens glued to the top, leaves the prism and hits a second lens, then it hits two more 45 deg prisms and ends on the lit grid screen. Adjustments I have attempted, rotating grid screen in mount (does not help), systematically adjusting the first mirror (this seems to only help center on the lit grid). If I focus past infinity, I can see the back of the prism (it seems a little off line but vertical). The prism is hard mounted with no adjustment. If I run through the focus range I can count all the surfaces the light bounces off. Please suggest any possible ides to why the grid is askew.
Thanks
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