[Jbunky86 (Jason)]

Hi everyone
I have a new gso F4 8" cf newt and qhy10 osc. Using a mppc spaced at 56mm which seems to give me the least coma. I'm still getting slight vignetting at the corners and I suspect my ccd needs to be tilted slightly.

What's the best way to figure out tilting? Is it a matter of taking flat frames and adjusting the collar? A sort of trail and error procedure?

Lastly would moving the mirror rearwards reduce vignetting? Or would that not make a difference because the focuser would have to move inwards the same amount to reach focus?

Any help would be great

Thanks jas