Early Jupiter-12 samples

[darkkavenger]

that is one lovely contax you have! 😉

 

[myequation]

I had to bump this old old thread.

I wish we could compare photos taken with these j12 versions.
My interest is in the quality of old KMZ vs Newer models.

Would the modern coatings be much improvement?
Is the optical quality better with the early lenses?
Speaking as if we had CLAd versions of all the j12 lenses under testing.

 

[Peter_Jones]

I have a 1952 LTM J-12 and a 1986 Kiev-mount version.

The 52 has blue coating, the 86 purple.

Once I get both an LTM and Kiev body working correctly (or close enough) I'll test them out with some colour print film to see what (if any) differences there are.

 

[rxmd]

H. Scherer states in his website that the design is copied on the Biotar and that one cannot see through a Biogon lens (?).

I think he is in error here. As far as I know there is no 35/2.8 Biotar for the Contax (this alone makes me sceptical about the accuracy of his statement). There is a Biometar, which looks like this:

(from Pacific Rim's CZJ Biometar 35/f2.8 page)

Look at how close the lens sits on the surface. There's no way to do that with a Jupiter-12, unless you cut a hole in the table.

Then you have the original Biogon 35/f2.8, which looks like this:

(from Pacific Rim's CZ Biogon 35/f2.8 page)

Now if that is not the model for the J-12 I don't know what is. I assume the folks at Pacific Rim know their Contax lenses good enough not to fall for a Russian copy. Note also that you can see the edge of the front element through the rear, something you shouldn't be able to do according to Scherer. To me it seems that Scherer is simply wrong in this case.

 

[myequation]

wOW finally a good picture of the Biogon rear.

I took your image and complied a comparison chart below.
Notice how the early J12 match exactly but later designs have no metal rings around the optics

 

[Peter_Jones]

Here's my pair of J-12s