Thanks for the link. I'm probably missing something, but while I see that this is a .5 focal reducer, I cannot tell (or do not know how to tell) what this would reduce an f/10 SCT to. Would it be an f/5, or am I way off base here? The ad does not give the f/ratio.
It would screw into the 1.25 in. nosepiece thread and give you a f/5, approx depending on the length from the chip, but I do not know how to figure the exact....