LTM to M adapters and lenses

I noticed that a few Leica lenses from the late 50s and early 60s come in either screw mount or M mount. The summaron and summicron to be specific. Do the screw mount lenses perform equally on an M body? The adapter acts like a washer that adds to the distance from the focal plane, no?
Do the M mount versions not have the infinity lock? It wouldn’t be needed for dedicated M mount lenses I assume.
Thanks.

I don't know about the infinity lock, but as long as the adapter is the correct 1mm thickness there is no difference.

When choosing an adapter, make sure you get the right version to show you the right frames in your Leica M finder.

Thanks. Good point about the frame lines. If they are indeed the same I don’t see a reason not to get a screw mount lens. Cheaper and more versatile.

Unless you want to use your lens on LTM and M bodies, I would consider buying a modern Voigtlander or even a Zeiss lens instead. The price should not be that different and you would get a lens with modern coating and lesser chance to be damaged.

I had a Zeiss biogon 35mm f2.8. It was an amazing lens that you could not get to flare no matter what. I miss it now. Now all my filters are 39mm and I don’t wanna buy more accessories

The LTM to M adapters work fine. I have a few LTM lenses I use on both M and LTM bodies and it does broaden your choices and the results are indistinguishable from newer lenses unless your comparing with ASPH lenses at F2. The collapsible Summicron LTM lenses are a good choice. Be careful about condition. Best to buy older lenses from reputable person with return options or who claim CLA with actual evidence to back it up.

Old Leitz lenses, LTM or M are prones to haze, separation, fungus and have very soft glass. They are good for show up status and as collective items.
For less money and better performance you could get new, NIB, with warranty Cosina made Viogtlander VM lenses.

That’s not what I hear and read everywhere else.
Zeiss Cosina I agree are beautiful but I had a Voigtländer Nokton and can’t recommend it.

Ko.Fe. said:

Old Leitz lenses, LTM or M are prones to haze, separation, fungus and have very soft glass. They are good for show up status and as collective items.
For less money and better performance you could get new, NIB, with warranty Cosina made Viogtlander VM lenses.

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ericdan said:

That’s not what I hear and read everywhere else.
Zeiss Cosina I agree are beautiful but I had a Voigtländer Nokton and can’t recommend it.

Click to expand...

I look at eBay, purchased, CLA’d old Leitz lenses. So with lenses I had it is first hand experience. .And those problems are wide known. Where are documents and videos how to deal with old Leitz lenses issues. I wasn’t inventing it, just google searched. No idea from were your info comes from.
Also from internet I knew about Nokton 35 1.4 as problematic lens and waited for MK II. No plans to sell it.

I agree the three main issues with the older Leitz lenses are haze, soft front element damage, and fungus etching the glass. A CLA can remove haze but it will come back in a few years. A CLA can not help much with the other issues. Also, there is much tinkering with lenses by laypersons, which broaden the variability of performance IMHO. If such a landscape (or minefield) seems overwhelming then I agree with Ko.Fe. To find a great example of some of these old lenses has never been easy but worth the hunt if your so inclined.

I have got almost not optically damaged Summar and Summarit. Just have to clean layer of smudge from one and kill one small fungus spot on the other. They were without scratches on lenses. I went from first 50mm Cron to all versions up to four. I had other old and not so Leitz lenses. I used them for at least on year and took hundreds of all kinds of photos with them. Sold and no regrets.
Right know I have Summarit-M 35 2.5 which I purchased new at discount price, because it is not popular lens for status and show ups. This is the only Leica lens I'm finding worth to keep because price, performance, size and build are optimum for me.
I also have version III Cron 50, I traded for IV which has plastic aperture parts and this one is stuck in sale on discounted price because among clueless Leica snobs it is bashed as bad lens. Version III Cron is just as good as IV, made with all metal, no plastic, but among Leica snobs been clueless is part of the club. They are repeating same mantras and myths without looking at images and comparing to other lenses.

Yea, I don't know much about the particular bits and parts inside. I have over last 30+ years purchased good used lenses and cheap messes. I learned not to automatically pass over a cheap mess and not all good used lenses preform as well as they should. The market I think is terrible for used Leica lenses these days. I have the impression all the good performers are never being sold and all the poor performers are endlessly circulating.