This week I received a Nikkor 5cm F2 in Leica Thread Mount "for Parts". The lens exhibited too much flare, especially when stopped down. The culprit was the front element: lots of cleaning marks in the center of the element.
This is a later Nikkor 5cm F2, Black ring with the F-stops marked. The construction is different from the earlier lenses. The namering comes out, and the front element is removable.
Even though the front element from a Jupiter-8 fits PERFECTLY in place, the focal length is wrong. The overall focal length of the lens is reduced, and cannot be corrected by changing the shim.
The optics module from an S-Mount lens is not the same as the LTM lens, and will not fit into the mount. I'm not willing to break the front element of my S-Mount lens to see if it will fit this one, the optical formula might have changed.
SO: remember the Summicron with the bad front element that I used an eye-glass repair kit on? The problem was applying the coating evenly. So I thought about what Leica did in the 40s: made a solution of the coating material in a liquid that woud evaporate. The spun the glass to even it out.
I mixed some of the fluid from the eye-glass repair kit in Ronsonol, put the front element in an ultrasonic cleaner, and slowly dropped the solution onto the lens. It evened out, moved to the edge- used Q-Tips to sop up the excess.
Tested it on the Olympus EP2 using an M-39 to u43 adapter.
Wide-open, straight into the Sun.
A little less stress. At F2:
At F5.6:
This is a later Nikkor 5cm F2, Black ring with the F-stops marked. The construction is different from the earlier lenses. The namering comes out, and the front element is removable.
Even though the front element from a Jupiter-8 fits PERFECTLY in place, the focal length is wrong. The overall focal length of the lens is reduced, and cannot be corrected by changing the shim.
The optics module from an S-Mount lens is not the same as the LTM lens, and will not fit into the mount. I'm not willing to break the front element of my S-Mount lens to see if it will fit this one, the optical formula might have changed.
SO: remember the Summicron with the bad front element that I used an eye-glass repair kit on? The problem was applying the coating evenly. So I thought about what Leica did in the 40s: made a solution of the coating material in a liquid that woud evaporate. The spun the glass to even it out.
I mixed some of the fluid from the eye-glass repair kit in Ronsonol, put the front element in an ultrasonic cleaner, and slowly dropped the solution onto the lens. It evened out, moved to the edge- used Q-Tips to sop up the excess.
Tested it on the Olympus EP2 using an M-39 to u43 adapter.
Wide-open, straight into the Sun.
A little less stress. At F2:
At F5.6:
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