A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Fleming
Date: 2018 Oct 26, 15:32 -0700
I have understood that the orange horizon filter was designed to improve contrast in viewing the horizon through haze. Further the use of a colored filter as opposed to a neutral density filter can improves the sharpness of edges by removing chromatic aberations.