Hi
I am using a filter wheel with lrgb and NB filters so will have to focus between filters.
My only concern is the vignetting and light loss cause I have to move the mirror up for the 94mm spacing reqmt of the rcc1 and I had to move it up for the 2.5" moonlite's 74mm height.
Edit: your post in another thread answered my question on how the guide star moves in one direction and the galaxy in another.
this makes it clear. scary though. is ONAG the only way around this if we want AO to negate or improve bad seeing?
http://www.footootjes.nl/Astrophotog...hy_Seeing.html
Cheers
Alistair