I have added some photos showing my
very amateur setup and what you can expect image quality wise from single frame exposures of up to 30 seconds.
The lens on the DMC-FT1 Panasonic is fixed, so I don't have to worry about the zoom lens issue on my compact camera. With the camera mounted there is approx 8mm between the lens and the eyepiece glass.
As 2stroke has already mentioned, I only use the optical zoom feature and avoid using digital zoom. Optical zoom for me is a lowly x4.6 maximum. I don't rely on the camera to focus as it always gets it wrong when used for afocal at night. Instead, I let the camera think it has achieved focus and then use the telescopes focuser to get it as close as possible. Even this is a little hit and miss and multiple shots are usually required to get a reasonable result.
Afocal imaging is never going to get really high quality results but it is still a lot of fun and a great way to give others an idea of what we see at the eyepiece. That said, the views at the eyepiece are always better.
Keep at it.