Originally posted by Achromatter My turn to bite. How do you this?>
I have a set of the cheap tubes similar to the ones shown, the sections screw together but the thread size does not match a standard filter, so I don't have adapter rings that would fit (and none may exist). Depends on the specific tubes of course. Looks like the OP may have used electrical tape?
My tubes used this way form a tight fit with either my A 50/1.7 or M 50/2 (I'm not de-glassing either though
), so alignment shouldn't be a big issue and you could confidently epoxy one of the short tube sections to your deglassed lens for more permanence (what else are you going to use it for?).
Skipping the tubes and reversing the attached lens (as Nass has mentioned), would take a standard reverse coupling ring.