Nikon LTM Lens Mount

[kafir2]

Hi board,
I'm asking some help this time: please take a look.
I just bought a beautiful Nikkor 135mm in LTM to use it on my IIIf and eventually on my M3 using the proper LTM-M adapter.
When I tried to mount the lens on the IIIf something very strange happened: the lens mount smoothly but when the screw ends and the lens is firmly screwed I have the tripod mount on the lens NOT facing backward but exactly 90 degrees more on the right, therefore pointing exaclty on the right of the camera (seeing it from the top).
If it was only for the tripod mount it wouldn't be a great problem (I prefer handhold photography) but:
- the rangefinder is uncoupled: the rangefinder cam on the lens is obviously not linked with the cam on the camera being the whole lens 90 degrees too rotated
- the focusing indicator is not visible from the top of the camera: in fact it is rotated 90 degrees on the left!
In the end the lens is not usable (except infinity).
Of course my camera screw mount is perfect: I use it with my Elmar without any problem.
And also the screw on the lens barrel seems perfect: it's a near mint ex&le of that fine Nikkor
So, I'm asking what do you think of this and, most important, how can I solve this strange problem.
Thanks in advance

ciao
k

-telemetro ok
-uso elmar ok

 

[tbc]

Paolo,
Not seeing your lens, I would guess that someone reassembled the mount 90 degrees off. If there are 4 screws allowing the mount to be removed, you might try doing this and rotating the mount in the right direction. The focus cam should then be at the 12 o'clock position (top). Be careful not to lose any parts, even shims, if you try this.

 

[kafir2]

Dear Tom,
thanks for the reply and for what seems a very good idea.
Seeing the lens from the back I should see the focusing cam aligned with the focus mark on the barrel (just like any other LTM lens), am I correct?
A reason for this misalignement could be an approximative attempt to clean the lens or something like that.
BTW the four screws are present and I'll try this evening to rotate the mount.
Apart aviod losing parts, is there anything that needs to be done/checked/known before attempting that kind of operation?
I'm asking that because it will be the first time that I mess with lens disassembling
Thanks a lot again

ciao
k

 

[tbc]

Hi Paolo,
The focusing cam may be a 1/2" or 12mm wide strip of metal, and it should be aligned with the focus mark on the barrel (top).
I would clean the exterior of the lens before disassembly to prevent any debris from falling inside. I don't think you need to touch the optics. Make sure that you have a good fit on the screwdriver to prevent scarred screw heads or slipping and scarring the lens itself. Use alcohol or glass cleaner to clean parts before reassembly. Work over a big table, and if you can avoid working over carpet, you'll be glad if you drop any screws. Best wishes, Tom

 

[kafir2]

Thanks Tom,
I'll try it in the weekend: I've identified the necessary screws on the barrel (probably I have to remove just the final part of the barrel.
And yes, I wouldn't dare to touch the optics: it that effort is necessary I'll leave it to a professional.
I'll let you know the results asap.
best regards

ciao
k

 

[kafir2]

Dear Tom, I've solved the issue.
It's incredible but it wasn't a lens' fault!
It was the lens flange of my IIIf that was rotated by 90°!!!
In fact the camera was repaired (shutter of course) recently by a not-so-competent repairman of the shop that sold me the camera.
The problem was not apparent with my Elmar due to the shape of the rangefinder cam that insured coupling even with the rotated lens mount.
Now I fixed the lens mount and both the lens mounts beautifully with full rangefinder coupling.
I hope this could be useful to some other fellow member, thanks a lot again

ciao
k