CZJ Sonnar: Jupiter lens elements

[hwntw]

I have a collapsable CZJ Sonnar 50mm f2 with some rather ropey rear elements. My guess is worn coating, but I am not sure that the lens is actually coated or not.
It is not dreadfully bad but I wondered whether I could do a swap of the rear elements from a Jupiter-8 Contax fit lens?
Is this feasible?

 

[Sarcophilus Harrisii]

I have a collapsable CZJ Sonnar 50mm f2 with some rather ropey rear elements. My guess is worn coating, but I am not sure that the lens is actually coated or not.
It is not dreadfully bad but I wondered whether I could do a swap of the rear elements from a Jupiter-8 Contax fit lens?
Is this feasible?

If it is not "dreadfully bad", why would you want to? I suppose you might get more for it if you sell it. I suspect that in most cases, this is why people do it. Which doesn't necessarily make it right.

 

[hwntw]

Suspect all you like, can you answer the question? I wish to use the lens, I dislike your insinuation that I shall pass off a hybrid

 

[Highway 61]

This is not feasible (the barrels of the two rear groups haven't the same size and threads).

 

[Sarcophilus Harrisii]

Suspect all you like, can you answer the question? I wish to use the lens, I dislike your insinuation that I shall pass off a hybrid

I dislike your interest in ****ing up the originality of such a fine old German lens for the sake of your aesthetic sensibilities, so it seems we're square.

 

[newst]

To get pedantic.

The earliest J-8s, 1946 to 1948-9ish were made from Zeiss parts and Schott glass shipped from Germany to the Soviet Union as war reparations. If you have one of these the rear lenses would work but these are rare and expensive. Worth more on their own than your Sonnar. After the original glass ran out the J-8 lenses were re-computed to accommodate Russian glass. Close but not identical.