m ltm adapter on different bodies acts differently

[Michael I.]

Hi all!

I have a couple of leica bodies (m2 and m4), both cla'd.
I recently got a cheap fotodiox m ltm adapter to use a j12 on them and it fits perfectly (focuses to infinity, sits well) on the m2 but doesn't lock and seems to focus the rf off on the m4. Didnt see the pictures yet, so I cant tell how's the actual images are. Original leitz adapter work perfectly well on both.

Does this make sense?

 

[Dante_Stella]

LTM adapters inject their own tolerances into the mix. With a 50 mm lens, differences in adapter thickness a are relatively insignificant because the rangefinder cam and the lens cell move at the same rate. So you may not get perfect alignment at the physical infinity stop, but the rangefinder distance and the focus distance will match all the way.

With wide-angle or telephoto lens is, the situation is different because the relationship between the movement of the rangefinder cam and lens cell is mathematical relationship and gets disrupted by an unexpectedly thick or thin adapter.

Dante

 

[raid]

Good point, Dante. Thanks.

 

[Michael I.]

that is very illuminating, thank you Dante.