"not sure if they're sharp..."
A couple of months ago I was reprinting some old negatives of close-ups, including a homage to Weston of a shell. I made a 16x20 and thought it was made with my Hasselblad and a close up ring. Then I noticed the lack of notches on the left side. It was shot with my 3.5 F model and a #2 Rolleinar.
Damn these things are good. Light to carry too. I alway have a #1 & 2 in my bag.