I love My I 22s , but then I prefer the feel of an old Elmar to that of the Zeiss Helios lense on my Kiev 4m . The sole collapsible which will mate with my M 8 is a Fed 50 / f. 3.5 which does not foul the adapter - but now I have 3 x I 22 rigids which have been rebuilt by altai to play with !
The Fed lense is superb - bright , clean and sharp , with a better feel than my black J 8 .
In fact , I am aquiring a couple of those oh so underated I 50s which came with the 42mm Zenit B , for use with my Pentax K 10 D .