Bahtinov mask for Vixen Ark 80mm binocular

thingiverse

The Bahtinov mask is modified specifically for Vixen Giant Ark 80mm binoculars. The inner diameter of the ring measures 94 mm and fits snugly onto each binocular's rubber cover. It can be used with Vixen Giant Ark 12x80, Vixen Giant Ark 16x80, Vixen Giant Ark 20x80, Vixen Giant Ark 30x80, and Vixen Giant Ark 16-40x80 models. PS: I'm unsure if it functions properly since the focal length divided by mask step should fall within the range of [150,200] or [50,66]. Given that this mask has a 4mm step and an unclear binocular focal length, I suggest a focal length of 300mm for these binoculars, as it appears natural for their size. PPS: Tests show that it works well with point light sources (stars should work similarly) even with these mask parameters. A relationship of 75 is considered good according to the source, indicating optimal focusing when the second-order spot falls within [75,100].