Leica lens version ID

[colyn]

I picked up a Leitz Summicron-M 90mm f/2 lens and was wondering how to determine which version it is. It's made in Canada with E55 filter mount with built-in lens hood and the s/n is 3474xxx

 

[Gabriel M.A.]

Sounds like a version II lens...not an expert on them, though. Mine is a Version III (shorter, lighter, pre-asph, Made in Germany, E55)