[KOML] Ground glass Back

[Tom Cogbill <zloi@seanet.com>]

It is interesting to note how many variations of the K-O series were
produced.  It seems just about everybody has something different about
theirs.  My 90mm lens requires a series filter, and so I just assumed
the 180 and 58 I recently got would also, but lo and behold, the 180
takes a standard 67mm!  Is this, 'go figure,' or did somebody make a
modification along the way?

Clive--
Thanks for the 'close-up' info--pretty much as I suspected.  BTW, this
is the second or third time I've heard about this "ground glass
back"--but I have to confess, don't have a clue what this refers to.

--Tom