A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Tony Oz
Date: 2019 Mar 28, 05:03 -0700
If the mirror is translated a little, that will not affect the rotational center of the index arm. It will waste a little light (if the movement results in some vignetting), but that's it.
Though this is very counter-intuitive after lots of thinking I agree.
The fact that one may swap a rear-side mirror for a front-side mirror (and vice versa) without any harm - is the Good Thing! Now I can order a front-side mirror with the SiO coating (like here) for my FREIBERGER. With a benefit of lesser light attenuation! I can ask them to put the reflective layer on both sides - for redundacy! If the frontal side gets badly scratched - I'll simply flip the mirror.
Not sure if such swapping works for the horizon mirror though... With the rear-side reflection I get both the horizon and the body refracted, with the front-side mirror only the horizon refracts. Must think on it more.
Thank you very much!