Visibility III / V
RC reducer from Germany for the test. Problem: the in-travel of the focuser is not enough. The main mirror must be raised approx.
SN tube collimation is always an interesting chore
1.Concentrate the repair glass
2. perform translation and rotation of the deflection auxiliary mirror
3. center the tube of the open main mirror head on the auxiliary mirror with collimating screws
4.install the main mirror
5. Cheshire's 45-degree aperture with white light (tube end closed) and main mirror collimation screws centering the image of the correction glass "blue Ghost".
Thus, the SN tube is optically collimated.
Be sure to mark the position of the correction glass in relation to the holder, the position of the main mirror in relation to the holder and the position of the holders in relation to each other :-)
The TS reducer with a full 0.67X produces unwanted stars. It's a good idea to change the back focus from 80mm-> 65mm, giving a factor of 0.75X and a tube f: