This 1950 KMZ Jupiter-3 was originally made in Contax/Kiev mount, and looked like it had never been used. It probably was not. The focus was way off, the optics module was held in with sewing thread, there were no shims to remove to correct the front-focus problem, and some set screws were never put in. This lens is a mix of Russian and German parts which just did not work together. I put it into a KMZ LTM mount, shimmed for optimal use close-up and wide-open. Wide-open and close-up on the M9: Probably the first in-focus portrait ever made with the lens. The focal length was way off, and the lens could not be reliably used past about 10ft. Focus on the fence, tree behind it is in better focus. Infinity focus was unusable. Actual focus fell behind the RF as you moved to infinity. The focal length was much too short for a Leica, and would be even worse on a Contax. The field curvature also seemed very high- focus at edges was much closer than that in the center. First Jupiter-3 that I’ve ever had to increase the focal length. This is done by moving the rear triplet out. I used Teflon tape made for plumbing applications. This is a trial-and-error process, move the rear element and then change the main shim to get the focus correct for both close-up and infinity. Digital cameras are great for this. It took about four attempts to get the focus where it is now. When finished, an extra 0.15mm was required for the main shim, and the rear triplet was moved out about the same. The focal length was increased about 1mm, based on the extra 0.15mm required for the main shim. Close-up, and wide open: and distance at F1.5: The focus is fairly even across the fence, the field curvature seems to be tamed. I believe the spacing for the optics is now closer to the intended design, aberrations are not as wild. This lens seems to be the “missing link” between ZK Sonnars and Jupiter-3’s. Or it was assembly practice. I had another 1950 J-3 that was much like this one, but the focal length was much too long and the rear triplet could not be moved in far enough to correct the error. I parted it out. Two 1951 J-3’s: fixed one by moving the front optics to a new fixture and a new rear triplet, fixed the second by changing the rear triplet. I don’t know if all of the early J-3’s had issues, but the four that I’ve worked on were unusable. The 1953 J-3’s: all five that I’ve shot with were as good as the wartime Zeiss Sonnars.