Ev
I recently bought a book from Bintel entitled "Introduction to webcam astrophotography" by Robert Reeves. ($69).
It has some very interesting content on collimation on different types of telescopes, easy to follow instructions, and much more on focussing techniques.
It also has a wealth of knowledge on other subjects, not only imaging, such as working out the real focal length, not the one stated in the manual.
This book is a must for any astronomer.
My knowledge has increased a thousandfold, from idiot,
to almost competant,
and I'm only half way through the book.
Mike.