Originally posted by ducdao Main reason to buy a Kipon adapter is because it has the inner flange. It allows Auto M42 (no A/M switch) to stop down. Besides, the Kipon adapter is not that cheap, it's about $30 due to its rarity and inner flange design.
you can get the same thng, including the inner ring for auto lenses from B&H for $15 made by bower.
That is the one I have. Most comments about the screw being too long etc are related to this unit.
ALso, on my bower unit, the tolorances are such that the spring sticks up and binds against the base of the lens, or did until it met my work shop,
the sad point is that unfortunately thrid party parts sometimes don't fit together as well as ones designed and made by the OEM, if you have the patience and skills to resolve the demons then they can be a bargin, if you don't they can be a pain in the &$$