Converting a Voigtlander M mount to thread mount

[robertcambab]

I have a Voigtlander nokton 40mm f 1.4 lens that is m-mount. Does anyone know if I can get this converted to thread mount to fit my IIIf and would there be any issues with this regards compatability with the focusing mechanism?

 

[rxmd]

The focusing mechanism is the least of your worries, the rangefinder movement relative to the film plane is the same.

You'd have to have a new rear flange machined which is slightly recessed and thinner by 1mm, and narrower to fit the thread mount. I guess it would be rather difficult.

 

[wjlapier]

Contact either SK Grimes, or Japan Exposure's Dirk Rosler. The latter has contact with MS Optical who do alot of lens conversions. The former I've dealt with in the past converting SLR lenses to Nikon f mount.

BTW, I recently purchased a lens from Dirk and it was one of the best buying experiences.

Either way, it's gonna be an expensive venture.

 

[B-9]

Voigtlander makes so many great LTM lenses why not try to trade?

You'll end up spending more time and money into converting your 40mm than itd be worth on your IIIF.

Just my opinion 😛

 

[hans voralberg]

Probably end up being 3-4 times more expensive than the original lens, get a Nokton 50/1.5?

 

[Roberto V.]

Probably end up being 3-4 times more expensive than the original lens, get a Nokton 50/1.5?

Yup, I agree with this. Or get an Ultron 35/1.7 if you prefer something a little wider

 

[johannielscom]

Actually I can understand this.

I've got the hots 😱 for a Konica M-Hexanon 50/2.0 in LTM, so it would then be the worlds first Konica L-Hexanon 50/2.0 lens. Loved that lens but nowadays all my lenses are LTM...

Oh well, I might settle for a Color-Skopar 50/2.5, already LTM and nice & small...

But that L-Hex 50/2.0 keeps nagging! 😀



[Topic-related mode ON]

I'm interested in companies that could convert a Nikkor 50/1.2 to LTM or M mount, any chance on luck with SK Grimes or Japan Exposures there?

[Topic-related mode OFF]

 

[hans voralberg]

There's a Taiwanese guy who would do that, may be some one can chime in 🙂 And I think MS-Optical via Kirk would take on just about anything.

 

[Never Satisfied]

I don't think the conversion would be that difficult. You'll obviously need an M39 donor mount and need to the take the M mount off, drill some holes in your new mount and presto LTM 35mm f1.4. Just make sure your LTM mount is exactly 1mm thinner than the M mount, then you can use an LTM adaptor to get it back to M mount if need be.
If you used a CV donor mount from a dead Ultron or similar, I think the mount would be spot on 1mm thinner but obviously you would need to make sure that the rear element and the focusing tab will fit through the M39 mount.

Good luck, Andrew.

 

[John Shriver]

The key question, of course, is whether the rear element will fit through the smaller hole in a L39 mount. Leica pretty quickly started making lenses that were infeasible in L39 mount.

 

[rxmd]

Yes, probably the deciding factor. I remember Tom A telling me about a discussion he had with the lens designers at Cosina about making an LTM version of the Nokton 35mm f1.2. The conclusion was that it was possible, but the thread of the LTM mount would have to be in the glass of the rear element 😱

And that would be rather difficult if the rear element is supposed to move during focusing.

 

[jonmanjiro]

And that would be rather difficult if the rear element is supposed to move during focusing.

I don't think the Cosina engineers got as far as thinking about focusing. Once they realised that to stuff a rear element of an effective aperture of f1.2 into an LTM mount would require threads in the rear element itself, they gave up on the crazy idea 😉