[Leica] Interesting problems with M39-Leica M adapter

[jbcollier at shaw.ca (John Collier)]

You could:
Remove the adapter from the lens, remove the camera baseplate and  
open up the back, use a locking cable release with the shutter on "B"  
to open the shutter so you can see through from the back. Now try to  
mount the adapter and see what is up.

Personally:
I would throw it away and get one that works properly. I have never  
had a problem with Leitz ones.

John Collier

On 12-Jan-06, at 3:11 PM, Martin Jangowski wrote:

> I recently bought a CV adapter ring M39-Leica M. The seller said it  
> was unuseable and sold it cheap. I couldn't think why something  
> simple like a adapter ring wouldn't work and bought it.
>
> Unfortunately, he was right. It really doesn't work... it can't be  
> turned far enough in the camera bayonet. There is about 10deg  
> rotation missing, it just stops and can't turned further.
>
> I examined the lugs and saw that the ring (a 28/90 version) had  
> some tool marks at the lug that moves the finder masks. Obviously,  
> someone tried to convert this ring from 28/90 to 50/75 or 35/135 by  
> removing material from this lug. There was some wear at the lugs,  
> but nothing like the smoothly working bayonet of my 1964 Elmarit  
> 90mm... that one looks bad, but works like a charm. The CV ring  
> doesn't have any dents or obvious damages, only the lug for the  
> finder has a filed front edge.
>
> When turning the lens, the bayonet lugs move under the slopes of  
> the flat springs under the camera lugs. The lens is held against  
> the bearing surface of the camera by these springs. Is it possible  
> that the filed off lug doesn't glide correctly under the spring but  
> catches it with its damaged edge?
>
> Unfortunately, it's impossible to see the movements of the various  
> parts. Does anyone have an idea if its possible to repair this ring?