Help me trace the story of this lens (Sonnar 1.5 5cm)

[Wolkengrau]

Hello everyone,

This is my first post and topic on this forum, English is not my native language, so beforehand, my apologizes for the clumsy mistakes. I registered because of a lens I can not properly trace, and maybe someone here will have an answer 🙂 . I acquired a Contax III months ago, coming with a strange lens, supposedly a Sonnar 1.5 5cm. I wanted to know more about it and checked its number to have a year of production and a particular model. It seems firt of all that it is a post-war Jena lens from 1948, but lacks some details, the red T, maybe the coating.

There are other oddities with the lens, its aperture goes until f16, it has a red dot unlike the German Sonnar, and lacks the small black metal piece after the inner lens, with a number. Also, the front ring is curved, it does not seem that it resort of the port of a lens hood. Also, I have a 40,5mm screw-on lens hood that does not fit.
The body seem to be of aluminium ? The colour does not match with the chrome of the Contax.

With my poor quality phone camera, a sort of purple very thin coating appears on the lens, but from the eye, the glass seem completely uncoated.

This lens is an enigma to me, could it be a Jupiter 3 with an odd and curious fake Sonnar rebuild, or a black market lens made of disparate pieces in the Jena factory with German glass and a Soviet body ?


Voilà, thank you to anyone who has an information about it or just curious about the lens. It does not really matter to me if it is a genuine Sonnar lens or a strange ripoff, and I have yet to see the first results of the lens. The camera just came back from a gentleman's atelier in Estonia, whose name is Oleg, and who was also curious about this odd lens.

Many thanks 🙂

 

[Sonnar Brian]

This is one of the Mystery 5.8cm F1.5 Sonnars, that appeared after the war.

Another irregular production Sonnar

Took the 5.8cm lens out to a local historic site, it is a pretty decent lens. These were shot at f4 on my Sony a7III, straight outta camera jpeg, no tweaks on my part. Lower contrast as may be expected from an uncoated lens, especially second pic that has bright light streaming onto headstone.

rangefinderforum.com

Mine is 2 away from yours. It is not a 5cm lens, but will be in good focus at infinity on a Contax. The actual focal length is closer to 5.8cm. Uncoated optics. Most of these are in Leica Thread Mount and have a "indexed Cam" to agree with the Leica rangefinder. No one has definitively tracked the origins of this lens. "Speculation" is they were made as Sights for German Aircraft (Stuka) diring the war. After the war, made into camera lenses. Maybe they were a trial run of optics. What is clear- a lot of work went into these, and they are decent performers. They are not Russian fakes. my speculation- transition lenses made after the war, before the factories were being reestablished.

My lens, and yours- take 40mm filters and hoods. I put my Walz filter and hood made for the Canon 50/1.5 on mine.

 

[Wolkengrau]

Thank you sir for you answer, if this lens was to be initially a sight, and transformed as you mention, that is for sure a very singular story, and a lens to treasure. Even if it is only speculations, the part of "unveiled mistery" over these early post-war lenses made in a chaotic moment, is something that interest me a lot.

New to photography, I am lost and do not know how to focus properly with a 58mm that presents as a 50mm lens. Will the rangefinder show the correct focus beside infinity, or is there a way to find with with a "static" difference between the rangefinder focus and the proper focus ?

Many thanks for the link to your topic, I am digging it, it's fascinating.

 

[Sonnar Brian]

Thank you sir for you answer, if this lens was to be initially a sight, and transformed as you mention, that is for sure a very singular story, and a lens to treasure. Even if it is only speculations, the part of "unveiled mistery" over these early post-war lenses made in a chaotic moment, is something that interest me a lot.

New to photography, I am lost and do not know how to focus properly with a 58mm that presents as a 50mm lens. Will the rangefinder show the correct focus beside infinity, or is there a way to find with with a "static" difference between the rangefinder focus and the proper focus ?

Many thanks for the link to your topic, I am digging it, it's fascinating.

My lens is made to be in focus at Infinity on a Contax camera. I think it is the only distance that the lens can be easily used.
It is "possible, not probable" that the lens came on a Contax body made specially for 5.8cm focal length.

It is also possible, but very slow and inconvenient, to make a chart to use the rangefinder of the camera to find the distance to the subject, look that distance up on the chart, then set the distance scale to a value that will produce the correct results for the 5.8cm lens.