Chardyboy wrote:
"I ... would like to attach a 'spotting scope' to the G3 - is this possible."
Yes it sure is. And imo it is a very cost effective way to get a great telephoto lens for the G cameras. I attach my G2 to a 4" (100mm) F5 Celestron spotting scope. Like most spotting scopes, it accepts standard 1-1/4" astronomical eyepieces which are usually adaptable to a camera. Many people use the Scopetronix (Scopetronix.com) Maxview 40mm eyepiece with the Canon G cameras. It attatches with an adaptor to the camera and then inserts into the 1-1/4" eyepiece holder of the scope.
You will have to zoom the lens to 1.8x or higher to get rid of vignetting. A barlow lens (usually around 2x some up to 5x) is a cost effective way to multiply the power of the system.
Most spotting scopes come with a 45deg corrector prism to get the image right side up and oriented correctly left to right. I find they work well, but tend to limit the capeable feild of view of a given eyepiece. A right angle prism generally alows the full feild of view, but the image is reversed left to right. If you're looking for the clearest brightest picture possible, you can set it up straight through to the eyepiece, but the image in the LCD will be upside down.
Go for it, and enjoy,
Keith