M mount to LTM adapters


wheresmycheese

Senior Member
Feb 9, 2009
1,819
5
38
Sicily, Mediterranean Sea
often we heard of LTM to M adapters. But does anyone knows if can get a M to LTM mount adapter as i wish to usem y M mount lens on some of my screw mount cameras :D

thanks alot!
 

Srono

Senior Member
Mar 20, 2006
579
0
16
i think it is impossible without modification on lense
 

raytoei

Senior Member
Jan 14, 2010
2,066
3
0
only the early summaron m mount has screws that once removed, could be used on the ltm.
the reason why it cant be done is that there is a distance thingy which was designed such that the
m-mount would be 1mm more than the ltm mount.
 

nicolasM

New Member
Aug 28, 2014
44
0
0
Singapore
what is surprising is that no body in the world has offered such modification
 

gommy

Senior Member
Sep 7, 2006
2,588
2
38
Moses' Hill
If there is is a M to ltm adapter, then you probably need a digital screw mount camera with live view for focus. For M lenses to be mounted and have RF coupling, the M lenses need to be recessed into the camera by 1mm. So with any adapter it would be like adding extension tube to the lens and you can't have infinity focus, only close range focus.
 

newghost

Moderator
Staff member
Sep 17, 2009
4,337
5
38
Ideally I could use a LTM lens on a screw mount body and also on a M body with an adaptor, that's also why my slight preference for LTM
 

Cactus jACK

Moderator
Staff member
Jul 12, 2004
3,935
3
38
Singapore (Kallang)
I think that the answer is already her in the thread...

if you notice, the [lens] LTM to M [camera] adapters is approx 1mm thick. this helps adjust the LTM lens outwards by that exact 1mm to the right distance for the rangefinder coupling and the flange distance to the film plane. this need for the rangefinding coupling also implies that it cannot e done the other way around. even if you did machine a [lens] M to LTM [camera] adaptor, the rangefinding coupling will be off. and because of the flange distance is further extended, the lens distance readings will also not be correct.

given that the LTM cameras are all film (no TTL live view), you would not be able to focus properly with it... unless, as gommy put it, you find a "digital screw mount camera". it's not to say it cannot be done.