split-pupil finder

This is a telescope finder that works based on the split-pupil effect.

The idea came from Jerry Oltion's website, you can find a complete description of the design and how it works in https://www.jerryoltion.com/Split_pupil_finder.htm

Here I adapted the idea to the available lens that I had. I uploaded the FreeCAD project file in case anyone else wants to make modifications.