hey
yes, the f/5 ratio of my 8" ratio is good for A(astro)P(hotography).
focal length 1000mm / aperture 200mm = f/5
the smaller that number the better for AP. you need less exposure time and you have a wider field of view. (I think...
I'm a noob, so don't take my word as a bible unless I sound as if it
is gospel.)
here , you can get an idea what your field of view with a telescope and your camera chip would be. (choose M31 for example from the white objects menu.)
if you click the red link "switch to visual view", it also covers the FOV for telescope and an eyepiece.
BUT -
my mount is an EQ5. max load 9kg as advertised by the manufacturer.
for AP, one has to almost half that advertised weight to be in the proper tracking range of a mount.
my mount is totally overloaded with the tube, the focuser, the dove tail bar, tube rings and camera - 9kg in total.
the tracking is horrible - almost unusuable. If I ever reach 20 seconds exposure without horrible oblong stars and tracking errors, then I can be happy. for visual, this has no noticeable negative effect, though!
this is gospel
that's why I suggested you consider the max load of your new mount when choosing a telescope. or at least bear in mind the effect it has.