Quote:
Originally Posted by alpal
Hi Richard,
Apart from introducing cantilever changes in angle causing instability -
moving the secondary mirror down towards the primary will
change the point at which focus is found.
That point is now setup so that focus in my camera
is achieved just as the coma corrector enters the inside of the tube.
I am experimenting with different designs here:
https://stellafane.org/tm/newt-web/newt-web.html
cheers
Allan |
well moving the primary would also change the focus point. If the offset is wrong and you want to fix it then you'll have to change something. if you don't want to cut new holes in your tube for a new focuser position, and you don't want to change the position of the primary or extend the secondary down because that will alter the focal plane, then what is left...?
You could get a new tube I guess, or the nuclear option of a whole new scope...