Contax/Nikon 50mm lenses?

[aoresteen]

My first Contax IIa I bought in 1978 and I currenttly use a IIa BD. I have a 50mm f/1.5 Sonnar, a 105 f/2.5 Nikkor 'C' and the CV 25mm lens.

I know that the telephotos have to be made for the Contax or the Nikon due to the difference in helical focusing.

I know that the Nikon S and Contax helicals are different but the wide angle lenses can be used on either with no significant problems.


OK, here's my question: What about the 50mm lenses?

For 50mm lenses that use the internal helical mount it seems to me that since the lenses don't have a helical, I could use a Nikkor S on Contax IIa with no problem or vice versa. The camera helical mount is matched to the rangefinder so it should focus ok if the backfocus is the same. I've read that the back focus is the same and that the back focus is not the same. So which is it?

I'm thinking about buying a Nikon SP 2005 and using my 50's vintage 50mm f/1.5 Sonnar on it. Will it work?

Thanks!

 

[xayraa33]

the Nikon used a Leica FL standard of 51.6 mm v.s. the Contax 52.3 mm on the 50mm lens, so at close range focus at full bore, the focus will be off,
unless the lens is shimmed to compensate for the difference.

see Dante's article.
http://www.dantestella.com/technical/compat.html

 

[aoresteen]

Thanks xayraa33!

So how do the 'Contax Lenses to Leica' adapters work? Seems like only the Nikkors would focus right but I read that a lot of people are using their Contax Sonnars on a Leica M?

Also if you shim the lens, won't infinity focus be off?

 

[Mazurka]

Those people probably don't shoot their Sonnars wide-open at close distances very often.

 

[xayraa33]

that is correct, most people would not shoot wide open and at a close distance with Contax lenses.
yes shimming the lens will make the focus off at infinity at large f stop openings but from f5.6 down it would be ok.
this is really a "best compromise" scenerio.
one very talented fromer member of RFF, adjusts (Kiev) Helios 103 lenses to be used on Nikon RF cameras by backing out the lens group assembly by one half turn out from the bayonette part of the lens.

 

[Terao]

I see Zeiss have announced a new version of the Sonnar in S-mount!

http://www.zeiss.com/C1256A770030BCE0/WebViewTopNewsAllE/D8072563C600B43CC125736300241538?OpenDocument

 

[furcafe]

Too bad they won't be offering 1 in Contax mount (a fact that some might find ironic).

I see Zeiss have announced a new version of the Sonnar in S-mount!

http://www.zeiss.com/C1256A770030BCE0/WebViewTopNewsAllE/D8072563C600B43CC125736300241538?OpenDocument

 

[micromontenegro]

I found it ironic (even if perfectly logical) when the ZI camera came out in M mount. Now I am simply flabbergasted.

 

[Terao]

Oh, I thought the mounts were the same? Or is it the age old offset issue that will mean it won't reliably focus in a Contax helical?

 

[furcafe]

The mount attachment is the same, but yes, per xayraa33's post above, the helicals don't move the lenses the same distance because of the difference in focal length.

Oh, I thought the mounts were the same? Or is it the age old offset issue that will mean it won't reliably focus in a Contax helical?

 

[Sam R]

Why a new SP

Why a new SP

There a alot of fine vintage SP out there for alot less than a replica. Get the real deal and buy some good glass with the thousands you save

My first Contax IIa I bought in 1978 and I currenttly use a IIa BD. I have a 50mm f/1.5 Sonnar, a 105 f/2.5 Nikkor 'C' and the CV 25mm lens.

I know that the telephotos have to be made for the Contax or the Nikon due to the difference in helical focusing.

I know that the Nikon S and Contax helicals are different but the wide angle lenses can be used on either with no significant problems.


OK, here's my question: What about the 50mm lenses?

For 50mm lenses that use the internal helical mount it seems to me that since the lenses don't have a helical, I could use a Nikkor S on Contax IIa with no problem or vice versa. The camera helical mount is matched to the rangefinder so it should focus ok if the backfocus is the same. I've read that the back focus is the same and that the back focus is not the same. So which is it?

I'm thinking about buying a Nikon SP 2005 and using my 50's vintage 50mm f/1.5 Sonnar on it. Will it work?

Thanks!

 

[Sonnar Brian]

> I'm thinking about buying a Nikon SP 2005 and using my 50's vintage 50mm
> f/1.5 Sonnar on it. Will it work?

I modified a classic 50mm F1.5 Sonnar. I moved the rear elements in toward the front slightly to shorten the effective focal length, and adjusted the variable stand-off ring so that it would focus close-up and wide-open. Infinity focus is good, the result of the shortening of the focal length.

I've done the same with the Helios-103 for the Nikon.

Late Zeiss Sonnar 50mm F1.5, wide-open at close-focus on the Nikon S3.

Tight Crop: