[masraum]

Originally Posted by Jim Richards

I imagine for long exposures, a person needs a tracking mount. Or is there some technique that works for manual mounts?

Yes, for long exposure, you absolutely need a tracking mount, but even then, if you are doing long focal lengths, you can have issues with just an auto tracking mount. Most folks will use a guide scope. I think the general idea is to mount a smaller scope with a smaller camera to your main scope, put your target or a target in the center of the view, then your computer will monitor the image in the secondary scope and make fine adjustments to the tracking over time.

Cost if you want to do AP can add up very quickly.

The good news is that you don't need as much exposure time now as you once did, well, you do, but you don't. Instead of trying to take a single long 2 hour exposure of an item, lots of folks will take many 5, 10, 15, 20 minute exposures, and then use something like photoshop or one of the specialized bits of software to stack the exposures electronically. I've taken static exposures of a second of bright objects like Andromeda or Orion's nebula and "stacked" 50 or 100 together to make fun images. They aren't award winning, but I took them and you can see detail in them that you can't see with your eye viewing through a scope (well not my scope in my yard).

Here's one of my favorite pictures that someone else took of Orion. It's the whole Orion constellation. I think this is an effort of a year or more taking many, many shots and merging them together.
From Here: Orion, from Head to Toes | Deep Sky Colors - Astrophotography by Rogelio Bernal Andreo


Here is a huge version.
http://deepskycolors.com/pics/astro/2010/10/mb_2010-10_OrionWF.jpg