LTM Nikkor-SC 5cm F1.4 "incredible two-headed transplant"

[Sonnar Brian]

Some 20 years ago I picked up an early NKJ Nikkor-SC 5cm F1.4 in Leica Mount, and a first-batch Nikkor-SC 5cm F1.4 in S-Mount. The latter- $30 with a Nikon M-Sync. The problem, someone had crushed the filter ring to make it take 40.5mm filters. I straightened it out and attached a Series VI adapter to it, works well. I picked up a front group from a later lens, and discovered the diameter of the fixture and optics was larger than the early lens. Collect enough lenses of one type made through their run- I believe the switch-over took place much later than the change to NKJ from NKT marked lenses.

A few months ago I picked up an S-Mount NKT 5cm F1.4, and this week picked up an NKJ 5m F1.4 in LTM. And again- the filter ring was a mess. Glass is good.
Shown with the later front group that I know to be incompatible.



What I decided to do: swap the glass between the LTM and S-Mount Nikkor. I have way more S-Mount lenses.
The LTM lens was $150 due to the filter ring being dented and the aperture ring being difficult to turn. All Better Now.
The NKT lens- $80 for parts. "Better than described", cleaned up beautifully when I got it. Had internal haze.

 

[Sonnar Brian]

After the transplant, the most difficult part was making the shim for the LTM lens. Braided Wire, 0.3mm. After this- I did straighten out the filter ring which can now take a 43mm filter.



The LTM Lens- use a spanner to remove the rear retaining ring.



The Shim used is common with the 5cm F2 LTM lens. It is different radius from the S-Mount shims.

The S-Mount lens: use a rubber cork to take off the retaining ring.


Taking out the rear group: Nikon made a special tools for this, the slots are recessed. I made a tool for the 5cm F2. MOST of the time, you can grasp the rear group using a rubber cork. The S-Mount group came out easily. The LTM lens: a drop of lighter fluid required to loosen the threads.


I decided to swap the glass between the barrels. It works. The rear and front groups are scribed with the last 4-digits of the SN.


I tried splitting a J-8 shim, too thick the barrel would not go in. The braided wire worked. SO- in the end, the LTM focus mount and barrel with the NKT front and rear groups in it. Original shim of the LTM lens was 0.9mm, and the thickness of the braided wire is 0.3mm. Trial and error, the 1.0mm shim + wire was too thick.

 

[Sonnar Brian]

Close-focus and infinity using the RF. Spot-On.

 

[Sonnar Brian]

F1.4 and F4 pairs. Focus is good across range.

 

[Sonnar Brian]

Just the RF, no EVF to confirm focus. Wide-Open,

 

[Sonnar Brian]

F1.4 and F4 pair, flare test- into the sun.

 

[MarkWalberg]

Thank you for posting things like this Brian. Inspiring is not a strong enough word for this. It is great that you are getting these old lenses, that aren't working well as is, back to life !