Better instrucment for film astrophotos?

Hi

well, I'm considering a second scope just for film astrophotos. I finally picked up a good mount (EQ-6),
and I am considering the following scopes:
7" Maksutov-Cass, 8" (9.25" also) Celestron SCT, 7"
Maksutov-Newtonian (hmm), and a 10" Meade SCT.

My main targets are galaxies, globulars, and planetary
nebs... While I understand the rather obvious
observation that "aperature wins", I wonder if
there is an argument for superior clarity and contrast
in the Mak-Cass and Mak-Newt scopes. Also,
the 9.25" Celestron seems to have a good reputation
but 'better than average' optics.

I'd love to hear any informed opinions, especially if
you've imaged using those scopes. Also, I'm planning
to get an autoguider...a cheap one to be used on a
guide scope.

Appreciatively,

ak

especially when working with film several of your options aren't so hot. Aperture doesn't always win in astrophotography--speed and optical design do 99% of the time. The Mak-cass is a little on the slow side in my opinion. The mak-newt has speed, but the tiny secondary that gives it such great eyepiece views leads to severe vignetting on film, provided it's designed with the right focal plane distance to let you focus. The 8" and 9.25" SCT's would do well, but the 6.3 reducers out on the market are really crappy in my opinion...The 10" would let you use a Giant easy guider (one of the finest astronomy accessories out there). Guide scopes don't work too well with SCT's, I'd highly reccomend going with an OAG. Out of your list, I'd reccomend the 10" SCT (or an 11" Celestron). I'd also reccomend a few refracotrs you haven't mentioned as well.