Collapsible Elmar on Canon RF?

[adep]

Just wondering whether anyone here has actually tried a collapsible Elmar 50/3.5 on a Canon P or 7s? I've read that some collapsible lenses should not be used on them, but apparently there are some that are okay. Any personal experiences?

[mjflory]

Here's an experiment with what I believe to be an Industar 22, which is supposed to be about the same size as the Elmar. The fact that is says "Taylor" on the front -- well, that's another story. The lens has a very crudely machined lip at the rear (most un-Leicalike), but it mounts acceptably on my Canon 7. (I haven't used it on the Canon but I did take some shots with it on a Leica IIIf this weekend and they were sharp and properly focussed.) Collapsing it is possible, but depending on the exact position to which the lens ir rotated, the rear lip may graze the light baffles or it may not. Even when it grazed the baffles, it seemed to do no harm, not even scratching them, but I wouldn't want to do it repeatedly. A writer on a Japanese site suggests gently reshaping the baffles with one's finger to mount a Jupiter 12 (another "problem lens" with the Canon) but I haven't wanted to do that to my Canon. The Industar (and therefore perhaps the Elmar) is a better fit than the Jupiter 12, but I don't think I'll be collapsing it on the Canon.

[airds]

Originally Posted by mjflory

A writer on a Japanese site suggests gently reshaping the baffles with one's finger to mount a Jupiter 12 (another "problem lens" with the Canon) but I haven't wanted to do that to my Canon.

We have already discussed J12's on Canons and came to the conclusion that earlier models were a no-no, later types fine. See these threads:


Jupiter-12 to Canon P? and
Jupiter 12 on canon?

[rover]

My 3.5 Elmar collapses fully on my Canon IV. I never thought to mount it on my P, I will do so tonight. Note, the barrel of the Elmar is shorter than that of the Industar 50 so if the 50 will work, so will the Elmar.

[mjflory]

We have already discussed J12's on Canons and came to the conclusion that earlier models were a no-no, later types fine.

Thanks for the links, Airds. Very interesting. I've noticed the difference between early and late Contax-mount J12s but never thought to try different-era Leica-mount J12's on the Canon 7.

[adep]

Mjflory, thanks for posting the photos, I can now see why there could be a potential problem. Rover, thanks for giving it a try, be careful!

[John Shriver]

A 50mm Elmar on a Canon 7s can bang into the baffle at the top of the shutter box. It's only the three locking lugs that stick out too far. If you go very gently and slowly, you could do it by feel so that the lug isn't pointing up while you collapse it. But it would be very easy to make a loud "skreek!" as it grinds along the ribs of the baffle.

The collapsible Summitar and Summicron are "no trouble", because they have the guide track along the barrel, and there's no tab pointing up while you collapse them. Of course, they don't collapse as small as an Elmar! Heck, the Summicron loses so little size it's almost pointless.

Summar has the same problem as the Elmar.

[adep]

John, thanks for checking that for me, I really appreciate it!!