JimBuchanan Offline Upload & Sell: On
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Here is an unusual setup using the Nikkor-S rangefinder 50mm. This lens is not a Sonnar design, but a Gauss type design introduced as the Olympia version in early 1960's and the re-issue or Millennium in the early 2000's.
I've always skipped over the normal focal lengths, but due to the frustration of fast 35mm solutions with field curvature and corner issues on Sony sensors, I thought about trying a fast 50mm focal length again to see if my style has changed .
However, this Nikkor-S requires some type of adapter to get it to an M bayonet for use with a TAP adapter. I chose to do it the hard way and fabricate an adapter due to the expensive, wrongway focusing, and loose fitting options on the market. My adapter fits snug, and it is part of a matched set with the TAP adapter and a Leicaist macro adapter, giving hardstop infinity on both. Because I didn't want to modify the TAP adapter, I machined the Leicaist adapter to match the TAP and then shimmed the Nikkor-S to Leica M adapter to get hard stop infinity on both focusing units. The Nikkor-S with the Leica M bayonet weights 250g.
With TAP-f/36, which parks the adapter at infinity focus after switching from AF to MF mode, there is no TAP focus movement due to the matched components. The infinity park position has been repeatable and precise, as commented in the TAP thread. So, now if I have an infinity target, I go straight to MF and the TAP goes to infinity park position. It probably doesn't make much difference, but having the infinity position at the extreme of the TAP infinity position, moves the minimum close focusing an inch or so closer. I measured 29 inches, or about .65 meter minimum close focus to the sensor, with the Nikkor-S 50mm re-issue.
To compliment the non-focusing Nikkor-S on the TAP, I have reworked a Leicaist macro adapter to include removing the Chinese glue and replacing with a lighter lube, added a focus tab, and adjusting its infinity stop. The focus throw is about 90 degrees which is really too quick, but the tab and ease of turning helps. Yes, the macro adapter focuses in the Leica direction, but the smoothness of the helical certainly isn't as good as a real lens helical.
Here with Leicaist macro focuser. Focus tab is visible around 7 o'clock at infinity.
All this work to get to an examination of image quality of a very obscure rangefinder lens on a Sony a7RII. To start, this is a modern gaussian design giving edge to edge infinity sharpness, here at f/8. F/5.6 is no different but the lens has a vingetting problem in the extreme corners and f/8 decreased that just a bit more. And a bit old school, as it took 4 stops down to get to ultimate infinity IQ. f/8 full frame
I don't see any mid field curvature as with the Ultron 35 and ZM 35 on a7RII, but maybe 50mm is less susceptible to the filter stack? f/1.4 full frame
Focus is on Saturn: f/1.4 full frame
f/1.4 full frame
f/1.4 full frame near closest focus
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