Ok just tested my mask made from thick felt on my Takahashi Epsilon 180ED and it works just awesome. The scope is 500mm and f/2.8 so focusing is always a PITA. I only tried focusing on brighter stars but it was very trivial to get perfect focus. The out of focus images looked very similar to the animation someone posted earlier. I could move the focuser in increments of 3 Robofocus steps (I think that corresponds to 1/1200 of a turn of the focus shaft) and see distinct changes in the diffraction pattern.
I thought about using a clear transparency sheet and printing the pattern but I was worried the sheet would slightly affect the focus position and so when I removed it then I would still be slightly out of focus. Make sense?
Previous
Index
Next
Flat
Re: Revolutionary new way of focusing! No less!
Edit
Reply
Quote
