We tried yesterday night to focus on shining stars. We used the black focus first, then the gold one, we understand the way it is supposed to work, but here is the problem : the image is never sharp, and when we defocus the star become « twisted » in one direction. To illustrate the problem, I joined a sketch of our problem. The quality of the draw is awfull, I’m sorry, we can’t use internet so I did what I could. Mathieu thinks this problem is well known and could be explained by the misalignment of mirrors. Would you know what problem it is? What would it be caused to? And what could we do to fix it?
Quentin and Mathieu