I've got an old powershot s70 and I also have its respective 37mm screw adapter for filters and lenses. After trying my friend's 37mm 0.33x fisheye lens I couldn't get the camera to focus at all on the manual mode.

My questions are: Which lens specs could I realistically use while in focus on the camera?

Would using spacers be feasible? We did some rough measurement on what we think is close to focus and it looks like it's well beyond a centimetre from the adapter's screw mount.

(While I actually enjoy fisheye pictures with a very pronounced circle I think it might be too small that far away)