Austintatious
Well-known
A while back I picked up an Industar 61LD with a Keiv mount attached to a NEX adapter from Grandseller @ Ebay. It is decent quality and works well. Now I can use my Jupiter 8M and Helios 103 along with the I61LD on my NEX 6 and my A7II. Happy camper 
Industar 61LD converted to Kiev mount & adapter by Carlos Yashinon, on Flickr
Industar 61LD converted to Kiev mount & adapter by Carlos Yashinon, on Flickr
rfaspen
[insert pithy phrase here]
Photo(s) of the beast? I'd like to get an idea what was done. At the very least, I'd like to see a cool and potentially unique lens. Always fun.
I probably would have forked out $50 for a converted J8M in Canon barrel if done nicely and correctly focusing, etc. Yes...., I think I would...
One of the best $50 ever spent on a lens.
The maker of this lens did a fair bit of machining, the optics rotate with the focus. He has to basically remove the inner portion of the Canon lens to do this.
The J-8M is good, it is the revised design. The original J-8M has a middle triplet that where the surface between the second and third element is flat, and the third element has a smaller radius. I suspect that centering the elements in this group were a problem. This later J-8M has a middle triplet more like a standard J-8, but bigger diameter.
raid
Dad Photographer
Your lens looks great, Brian.
1960s J-8M middle triplet-
I refused to believe this was a triplet as there were no seams, even after soaking in acetone.
KMZ J-8 on the left, 1960s J-8M on the right.
So I did some destructive testing.
And I think the flat surface and dissimilar radius of the 2nd and third elements is a reason why performance of the several J-8M's from the 60s that I've owned was awful. This is a design where the production people should have asked the optical engineers "how the hell are we going to align it?"
I refused to believe this was a triplet as there were no seams, even after soaking in acetone.
KMZ J-8 on the left, 1960s J-8M on the right.
So I did some destructive testing.
And I think the flat surface and dissimilar radius of the 2nd and third elements is a reason why performance of the several J-8M's from the 60s that I've owned was awful. This is a design where the production people should have asked the optical engineers "how the hell are we going to align it?"
The the old Optical Engineer retired, somebody threw out his ugly baby, and then did it right.
This is the 1970s J-8M.
The J-8M from the 70s on the left, KMZ J-8 on the right.
My 1970s J-8M converted to Leica mount is very good. I have it in the line-up to test against the new Bertele Sonnar when it arrives.
This is the 1970s J-8M.
The J-8M from the 70s on the left, KMZ J-8 on the right.
My 1970s J-8M converted to Leica mount is very good. I have it in the line-up to test against the new Bertele Sonnar when it arrives.