I've built a fast corrected newton, 780 mm focal lenght, f3.9, corrected with a Big Paracorr.
Spider is 45 deg vs focuser.
secondary mirror has 4.7 mm offset and it has been glued with offset.
I am now trying to collimate it, but I think I have issues with the positioning/rotation of the secondary mirror.
I am attaching a picture taken through the sight hole and hope someone can analyze it and give my some analysis and how to best fix it.
I think it is decently collimated but probably need to be rotated.
my procedure and my results:
1- I've tried to square the focuser using the tilt base of the focuser.
2- adjusted rotation and placement with a sight tube (very difficult)
3- collimated the secondary using a laser
4- collimated the primary with sight tube and barlowed laser, verified with cheshire
Collimation was ok in my opinion but the secondary was displaced up in the sight tube so I decided to correct the focuser tilt up/down
I repeated the above process and ended up with a situation in which the secondary was displaced down.
I readjusted the tilt in the opposite direction, collimated and the final result is the one attached.
In my opinion there is still at least a rotation error.
It would be nice to have an evaluation to understand if I am interpreting the results correctly.
Thanks a lot,
Edited by AndreaL, 25 October 2020 - 04:51 PM.