Herman Zhang Posted November 20, 2023 Share #1 Posted November 20, 2023 Advertisement (gone after registration) I want to get a L39 screw mount lens on my digital M240 and I am just wondering if the flange of the M mount is the same as the screw mount lenses. Also, does the rangefinder still works accurately if I use an adapter? Quote Link to post Share on other sites More sharing options...
Advertisement Posted November 20, 2023 Posted November 20, 2023 Hi Herman Zhang, Take a look here Flange distance of L39 and M. I'm sure you'll find what you were looking for!
frame-it Posted November 20, 2023 Share #2 Posted November 20, 2023 18 minutes ago, Herman Zhang said: I am just wondering if the flange of the M mount is the same as the screw mount lenses M = 27.80 mm M39 = 28.80 mm Quote Link to post Share on other sites More sharing options...
Ecar Posted November 20, 2023 Share #3 Posted November 20, 2023 If you use a good quality, 1mm-thick adapter you will get proper RF coupling (accurate focus is a different thing as it depends on the lens calibration itself). Rayqual adapters are my personal favourites, but they are pricey. A search on the forum will yield numerous results regarding LTM to M adapters. 1 Quote Link to post Share on other sites More sharing options...
dpitt Posted November 20, 2023 Share #4 Posted November 20, 2023 1 hour ago, Ecar said: If you use a good quality, 1mm-thick adapter you will get proper RF coupling (accurate focus is a different thing as it depends on the lens calibration itself). Rayqual adapters are my personal favourites, but they are pricey. A search on the forum will yield numerous results regarding LTM to M adapters. Be sure to select adapters for the right focal length! The adapter will select the frame it brings up. So different adapters for 28/90 or 35/135 or 50/75 Also, some LTM lenses will need cutouts for the infinity lock. 2 Quote Link to post Share on other sites More sharing options...
a.noctilux Posted November 20, 2023 Share #5 Posted November 20, 2023 I use happily screw mount lenses on my Ms for long. As said, some cautions to use these nice and plenty choices in different brands and periods. First thing is good quality (*) LTM-M adapter with thickness precisely 1.0mm . Three types is to choose from. Cutouts is needed for some lenses with focussing lever. (*) I had cheap adapters which sometimes are not possible to detach from M body, size or soft metal changed some adapters are not exactly 1.0mm, so problems in precision now I use only old Leitz adapters or Voigtlander ones. 1 Quote Link to post Share on other sites More sharing options...
BastianK Posted November 20, 2023 Share #6 Posted November 20, 2023 There is another issue, some M39 lenses have a slanted cam. Here also the radial orientation of the lens in combination with the adapter plays a crucial role. Had a lens like that, tried it with idk, 6 different adapters (including one of the expensive Voigtländer ones), never was really happy with the results. Quote Link to post Share on other sites More sharing options...
Anbaric Posted November 20, 2023 Share #7 Posted November 20, 2023 Advertisement (gone after registration) For an M240, I would probably get a Rayqual Type III adapter or equivalent. These are compatible with 6-bit coding and infinity locks. There are three types for the framelines required by different focal lengths (35/135, 28/90, and 50/75): https://shop.cameraquest.com/leica-screw-mount-adapters/rayqual-24/35/135-6-bit-coded-leica-screw-mount-type-iii-leica-screw-mount-lens-to-leica-m-body-adapt 2 Quote Link to post Share on other sites More sharing options...
spydrxx Posted November 20, 2023 Share #8 Posted November 20, 2023 I've used cheap Chinese ones, original Leica ones, and other brands. I like the Leica ones best, but usually others work just as well. Quote Link to post Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.