Changing mounts on a 35mm Summaron 3.5 lens

[carlprad]

hello

I own a Leica 35mm Summaron 3.5 "Bayonet-Mount" lens.

Unfortunately, It brings up the 50mm frame-lines instead of te 35mm frame-lines.

Can I buy a "bayonet-mount" that brings up the 35mm frame-lines and attach it to my lens?

If so, where do I buy this mount?

Also, Is it as simple as removing the old mount and attaching the new one?

Thanks

 

[Glenn2]

It's possible to file a little metal off the mount to make the lens bring up 35mm lines. Some users like to do this with 40mm lenses as they feel the 35mm frame is a better fit. Once this is done it will be very difficult to go back if you change your mind. Here's a link that will show what's involved in doing the modification.... http://photo.net/leica-rangefinders-forum/00CcwG

Glenn

 

[rlouzan]

DIY lens modificartion:

http://www.flickr.com/photos/sockeyed/607269471/

 

[FrankS]

Is your Summaron lens rangefinder coupled? With the lens mounted on a camera, does the RF patch move when changing focus distance on the lens? There was a version of bayonet mount Summaron that was made for the M3 camera that was meant to be used with an external finder and simply scale focused. This lens brings up 50mm framelines.

Another bayonet mount Summaron lens was made to be used with the M3 with goggles attached. This lens brings up 50mm framelines but the goggles de-magnify the viewfinder to show 35mm view.

Then there was a bayinet mount Summaron f2.8 made to be used with the M2 that brings up 35mm framelines on all M mount cameras except the M3 which has none.

 

[SimonSawSunlight]

the modification is dead-easy, I did it with a simple nail file and it took me about 5 minutes. just make sure you have your rear element covered (I just put some tape over the back part of the lens).

 

[Ronald M]

Don`t do it if it is a lens made with detatchable eyes and you plan on using it without them. It will nnot focus properly.

 

[Phil_F_NM]

The question of RF coupling is really important in this thread since there were a few variants of the lens. If have the scale focus model, you can find and ugly one of the LATER screw mount or M mount versions of the 3.5 variant and then transfer the optical cell from your lens into that helical with focusing and the correct cam angle.
Usually the f/3.5 Summaron have survived pretty well through the last 50 years so getting a donor lens may amount to just using the donor lens instead of the one you have.

If yours is RF coupled, you can file down a tiny bit of the keyed flange tab that pulls up the correct framelines. If your lens is one in which the goggles were removed there MAY be an issue of an incorrect cam angle giving a slight focus error. Some have not had a problem, some had. If your lens focuses accurately right now then it won't be a problem. You'll know. All summarons are fantastically sharp in the center and focus errors will be evident on your computer screen since you're using a digital M.

Phil Forrest