I picked up a second 1953 KMZ J-3 for "cheap", ~$75 with shipping. It was a mess. The front element had some serious coating damage and a chip, missing set screws, and the helical was mis-assembled. Spent a few hours working on it, repositioned the helical in the mount for infinity focus, tapped new holes for set screws, and replaced the front element with one from a 1982 "new-old-stock" J-3 from leonphotojazz65. I've used this optic with a focus mount, but it was not very sharp wide-open. Improved stopped down to F4. In this new configuration, it looks really good.
The new front optic has a yellow tint. Very Pretty.
But would it work? Using the TTL viewer, the overall sharpness at F1.5 was much improved over the original damaged optic.
Does not mean much until results are on film.
At F1.5:
Tight Crop:
F1.5:
Stopped down to F4:
And Infinity at F1.5.
Looks good throughout the range. Sometimes mixing optics changes the focal length, in this case it looks like both close and infinity focus is good. Dumb Luck.
The new front optic has a yellow tint. Very Pretty.
But would it work? Using the TTL viewer, the overall sharpness at F1.5 was much improved over the original damaged optic.
Does not mean much until results are on film.
At F1.5:
Tight Crop:
F1.5:
Stopped down to F4:
And Infinity at F1.5.
Looks good throughout the range. Sometimes mixing optics changes the focal length, in this case it looks like both close and infinity focus is good. Dumb Luck.
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