Astrophotography and digital SLR's

Hello everyone. I have a pre-2004 1st generation Konus 1793. I also own a Canon 20D and a 300D. I just have a few simple questions regarding the mounting and usage of my digital cameras on my telescope.

1. How do I attach the camera to my focuser? I realize that there are T-mounts made for SLR cameras, but is that all I would need?
2. Regarding question 1, if I purchase just a T-mount, my scope basically becomes a 2000mm f/5 lens. How do I increase the focal length? Is there some kind of barlow that is designed to mate with a t-mount? Am I also correct that if there is some kind of barlow (2x perhaps), that my scope then becomes a 4000mm f/10 lens?

Thanks.

James

P.S. I should perhaps state my reasons for wanting to hook up my SLR's. I'm still learning alot about astronomy, so serious astrophotography is probably out of my league. What I do want to accomplish is to take nice pictures of the moon or other planets without having to hold up my camera and lens to the EP, as I have done previously. The attached photograph of the moon was taken with a 25mm plossl and at the time, an Olympus C5050 help up to the EP. Now that I've upgraded to digital SLR's, I was hoping to get the most quality out of my lunar shots possible.

Attached Image:

You need a t-mount and a focuser adapter. The focuser adapter has a 1.25 or 2 inch snout that fits into the focuser, and a set of t-rings on the other side. They cost $15-20. They also come as part of an eyepiece projection, or "universal camera" adapter for about $45. Anacortes has them.

To double the focal length, all you need do is stick a standard Barlow in the light path. Or if you have a doubler for the camera, you could stick that in.

And yes, your focal ratio calculations are correct.

Alex