Camera to Instrument Mounting
The first decision that must be made for mounting a camera to a telescope, microscope, or some other type of instrument is wether the camera is going to be connected from it's lens or directly to the frame.
Connecting to the Camera
If you are connecting directly to the frame you will need a T-Ring. For my Canon 30D, I needed to order an Orion #05224 ring. It's a cheap part.
Connecting to the Instrument
Then, a prime focus adapter must be ordered to connect the T-ring to the instrument.