50mm Summarit F/1.5 Focusing Problem !!

[RussPhoto]

Hello everyone!

I’m getting out of focus images with LTM 50mm Summarit F/1.5 on my Leica M digital using the LTM to M adapter. All images at close distance are out of focus. When the lens is set to infinity lock, pictures come in focus despite that the rangefinder patch doesn’t reach and merge at infinity, visually it’s about one inch or so in difference. At close range camera rangefinder works ok but images come completely out of focus... I compared this Summarit with my another LTM lens (see pic.#1) and I noticed that focusing cam on Summarit is shorter!! I guess that’s the reason I’m getting out of focus images? Looking at the lens I don’t see any modification on it, all looks original to me. I also noticed that the focusing cam has an inner thread (see pic.#2) What is this for? For a ring adapter to compensate on LTM body? Any idea if Leica ever designed Summarits for other cameras, like cinema cameras?? I even removed the rear part (see pic.#3) thinking that someone put a chim but no, this is just one piece of metal. Any thoughts, ideas what could be that and how it could be fixed?? Using the lens on my Sony mirrorless camera with a live view is absolutely fine, no focusing issues and images look sharp on wide open at f1.5 in the center at close distance and infinity.

I will appreciate all your input and help! Thank you so much and happy holidays!

 

[Miles.]

If you search these forums you’ll find several threads relating to the focus shift that’s inherent to this lens, and that Leica/repair techs over the years have calibrated them at different apertures to suit preferences of photographers.

With that said, that might not be the only thing happening here. An amateur may have been inside the lens to address this issue and not correctly marked the positions of the helicoids.

If you aren’t versed with this issue I’d send it to someone experienced with rangefinder lenses.