will this set up work

[ollypenrice]

You need an apo for imaging and Andromeda is enormous, so only a very small scope will fit it all in. I took this with an 85mm scope and focal reducer (f3.9)

If I tried to take this in my big refractor I would need a five panel mosaic to get the galaxy on the picture.

Check out Psychobilly's link to CCD calc. That is essential.

Olly

[brianb]

why is a apochromatic better than a achromatic refractor?

Chromatic aberration. All refractors have it, ED doublets have about half as much as achro doublets with "standard" glass but triplets have 5-10 times less. Triplets can also have flatter fields. These things really matter with short focus instruments when used for imaging.

[turbotim]

Thanks for your replies! You all have been very helpful. When i get my scope i will post a pic.

[turbotim]

I have been taking advise and doing major research. And the more i research the more i realize i have to sell the farm:eek: So heres what i need help with, I would like a apo refractor on eq mount and i want to track for longer exposures. So when i find a set up its so expensive because its goto, Now i can get a beautiful apo refractor with eq mount and no goto, Now i enjoy finding the objects myself any ways. So they also sell a dual electronic motor drive for side reel tracking and i can afford this, its just not go to would this be good enough for me for now will those motor drives track right and is it a good idea?