I think it's that Industar-50 that has been voted the ugliest lens on earth. I have a couple of them on Zorkis, and what matters is whether they take pictures. For old-times' sake, I have others with the older-style collapsable lens version.
I don't have a 6 yet, but I'm looking. It seems that model wouod be about the closest to modern cameras, in that the back is hinged and the take-up spool is bult in, rather than floating around every time you take the back off of the other models.
I'm trying to build a series of Zorkies, 1 to 6. So far I'm still missing a 2 and a 6.
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