vrgard said:
Me, I wouldn't risk it now that we've confirmed that the collapsible Cron will extend into the body of the camera.
A lot of lenses will extend into the body of the camera. That's the whole point of rangefinder lenses. My 21 Skopar extends some 10mm into the body of the camera too, and it works fine on the M5. The question is really how far it extends, and I guess personally I'd just measure things myself, with the lens at infinity and collapsed, and then try out if it fits the M5. A new meter arm may be expensive, but if it fits, it fits.
The critical piece is the "hook" on the left edge of the metering stalk which protrudes in the direction of the lens mount. Even if the slot for the arm is quite far at the back of the camera body, this hook protrudes another two or three millimeters.
The dangerous thing about collapsible lenses is not mounting them in collapsed state, but collapsing them with the shutter wound. If the lens is collapsed before the shutter is wound, the metering stalk simply won't come up, as it's only driven up by a spring. You can easily test that with a LTM-M adapter ring: mount the ring, fire the shutter, wind (the arm will come up), fire the shutter, carefully hold your finger where the arm comes up, and wind on - nothing serious will happen to the arm. It's only dangerous when the lens is mounted already, the shutter is wound (so that the arm is in the metering position) and you collapse the lens against the extended arm. So another way to try should be to fire the shutter
without winding on (so that the arm is down), mount the lens in extended state, collapse the lens, wind the shutter so that the stalk comes up (either it does come up, or it is held down by the lens), and then to see if you get a meter reading against a light source through the collapsed lens - if you get a reading, the metering stalk has come up normally. I tried that with an Industar-22 to see where I have to put O-rings on the barrel. Try this at your own risk, of course.
Philipp
