what has a 43mm filter thread?

[schooler@apollo.hp.com]

Jack Campin writes:
 > I also use a Canon FL-mount 19mm with an adaptor.  Doesn't couple to
 > the rangefinder, but at that focal length it hardly needs to.  Is this
 > any different optically to the Canon screwmount 19mm?  It doesn't seem
 > to be a retrofocus design (has a huge internal projection that would
 > require mirror lockup on its intended body).

That's interesting: I've got two Canon 19/3.5 lenses.  One is the
non-retrofocus version you mention, but is a dedicated rangefinder
lens.  It has a feature unique in my experience: there is a detent in
the focusing ring at about 3 feet, the closest rangefinder coupling
distance.  The lens will focus closer, however; the detent just seems
to be a warning!  I also have the FL-R version that does appear to be
a retrofocus: MUCH bigger, with no rear projection.  The series VII
(or whatever, 90-odd mm) filter holder is pretty impressive!  I don't
know how the lenses compare optically, though reports say both are
quite good.  I've tried the rangefinder version, and mine seems to
have quite a bit of barrel distortion.

        -- Richard