Sonnar 5cm 1.5 - different serial numbers on front ring and rear element

[phanley]

I recently purchased a 5cm Sonnar f1.5 in Contax RF mount. I noticed the serial number on the front ring does not match the number stamped on the rear element housing. Preliminary research indicates they are supposed to match, but I can't find a definitive answer. Other than the numbers, the lens appears genuine. Front ring serial number is 2677872; rear number is 394705. Any help is greatly appreciated. Thanks!

 

[dexdog]

In my experience, the numbers on the front and rear should always match. The 267 series of CZJ 5cm f1.5 lenses generally date to between 1940 and 1942, although my 2011 copy of Hartmut Thieles's book of CZJ lenses says "beleg fehlt" which translates to English as "no records available" for the serial number on the front ring of your lens. Assuming that the full serial number on the rear element is 2394705, which is likely, this serial number corresponds to a production date November 21,1938 for 5cm f1.5 lenses. Looks like you may have hybrid lens. How does the lens perform? Given that it appears to be of comprised of different components of 5cm f 1.5 Sonnars, it might be a decent lens. Or a complete stinker if the collimation and shimming of the lens was not done correctly.

 

[phanley]

Thanks for the info, dexdog. I don't know how the lens performs yet. I'm waiting on a Contax-Leica M adapter to test it out. At this point I'm not sure whether to return the lens, or keep it and possibly pay for the collimation/shimming to be adjusted, if necessary.

 

[dexdog]

With any luck, Sonnar Brian will check in to give an opinion. In general if you do not have your heart set on a WW2 era CZJ lens like the 267 series, the post WW2 CZJ, Zeiss-Opton or Carl Zeiss 50/ 1.5 lenses would be good options, as long as you have evidence that they are in decent condition. A good Jupiter 3 in LTM or Contax/Kiev mount is also an option, although given the variability in quality control with some J-3s, I would wanna know that I had a good one before purchasing

 

[phanley]

I do have my heart set on a coated WWII era (or prewar) f1.5 Sonnar. They don't seem to pop up that often, which is why I'm considering keeping this one and paying for CLA. However, I've read that the postwar Zeiss-Option and Carl Zeiss versions are good.

 

[dexdog]

It is likely that the 267 series lens that you have purchased is coated. A CLA for such a lens should not be too expensive. In the USA, Youxin Ye does a great job on these old lenses, and usually charges about $100 USD or less. Youxin has done a couple of old CZJ lenses for me, and I have been quite pleased with the service.

 

[Sonnar Brian]

Dexdog has furnished all the answers- it sounds like someone replaced the rear fixture on this one. The SN on each is probably to track components more than absolute necessity.

The rear of the 2.34M Sonnar should work just fine on this one.

Is the rear triplet coated?

 

[phanley]

Thanks Dexdog and Sonnar Brian! The rear triplet is coated. I've YY clean several lenses for me, and I plan to reach out to him regarding this one.

 

[johank]

In the earlie fifties Zeiss offerd coating and cleaning on lenses, I had a Pal who had 35 mm with diffent numbers front and rear. It's possible your lens have had that tour too.