Perversity? Carl Zeiss Sonnar T* 50mm F1.5 Limited Edition Nikon S Mt

[julianphotoart]

My viewing of RFF is spotty these days so I honestly apologize if this question has been hashed out already.

Anyway, Zeiss is selling a new 50 f/1.5 Sonnar lens in Nikon rangefinder (i.e. "S") mount. It looks very nice indeed.

Isn't this sacrilege?

Please please tell me why Zeiss, of all people, is not offering the same lens in a Zeiss Contax (i.e. "C") mount????

It cannot be a matter of economics since I cannot believe that either lens will "pencil out" as profitable in the usual sense. Is there some perverse licensing issue that prohibits Zeiss from making a lens in a mount that it invented?

 

[jonmanjiro]

The market for S-mount lenses is small, but the market for C-mount lenses is smaller. Plus, President Kobayashi is a Nikon rangefinder fan.

Lovely lens, btw. It's too bad it wasn't made in the old Contax mount as well ...

At f/1.5

At f/4

 

[SolaresLarrave]

There's also the fact that Nikon recently put out a RF camera. That's another thing to consider...

 

[ZeissFan]

Although it's marketed as an "S" mount, it works fine in the Contax mount.

Remember, the helical for the 50mm lens isn't in the lens but the body (Contax and Nikon). The body helical is coupled to the rangefinder, and as long as the register between the Contax and Nikon S are identical (which they are at 34.85mm), then the lens should work identically on either camera.

I have no idea if Cosina had input on marketing the lens as the S mount rather than a C mount. But Carl Zeiss AG would have had the final say on how this lens was marketed and not Cosina.

As far as I'm concerned, I bought it as a Zeiss lens for the Contax mount, and -- if I recall -- it was marketed this was on the Zeiss site. It will be interesting to see what they might do if they try this with other focal lengths in which the helical is part of the lens. Perhaps, a limited edition in either mount ... I hope.

 

[jonmanjiro]

Although it's marketed as an "S" mount, it works fine in the Contax mount.

Remember, the helical for the 50mm lens isn't in the lens but the body (Contax and Nikon). The body helical is coupled to the rangefinder, and as long as the register between the Contax and Nikon S are identical (which they are at 34.85mm), then the lens should work identically on either camera.

Not true. There is a difference between the Nikon S-mount and the Contax C-mount. The new Sonnar 50/1.5 will focus correctly on a Contax body at infinity, but as you focus closer the true point of focus will slowly shift from point of focus indicated by the RF. More here (link).

 

[ferider]

But, if I remember right, in contrast to Contax, "normal" RF calibration of Leica and Nikon RF are the same, which might have facilitated Zeiss' "port" of the ZM Sonnar to SC mount (no changes in optical part required).

Roland.

 

[ZeissFan]

Not true. There is a difference between the Nikon S-mount and the Contax C-mount. The new Sonnar 50/1.5 will focus correctly on a Contax body at infinity, but as you focus closer the true point of focus will slowly shift from point of focus indicated by the RF. More here (link).

I had to think about this for a bit, and now I understand. It's basically because the 50mm lenses for either cameras weren't true 50mm but was 51.6mm for the Nikon and 52.3mm for the Contax, assuming that Dante Stella's information is correct.

I had made the erroneous assumption that both "normal" lenses were identical in focal length.

I wish the link to the Nikon site from Dante Stella's site was still active.

 

[ZeissFan]

OK, I found that link. And now it makes sense. Which now leads to the question of whether this lens will focus correctly on a Contax. Guess I'll found out soon enough. And if not, I guess I better hang on to my Nikon S.

 

[jonmanjiro]

You also need to take into account that the Zeiss helicoil rotates 270 degrees to go from infinity to minimum focus, and the Nikon helicoil rotates about 260 degrees to go from infinity to minimum focus.

See the comments by Brian Sweeney in this thread (link). Toobad he's no longer with us ....

 

[jonmanjiro]

With a Contax camera at minimum focus, you'll need to stop the S-mount Sonnar 50/1.5 down to about f4 or more to get what you're focusing on inside the DOF.

 

[julianphotoart]

Is there a standard discrepancy between the focus points of "S" and "C" 50mm lenses, or does the amount focus is "off" when using an "S"-mount 50 lens on a "C" mount camera vary depending on various factors? If it were a constant discrepancy, then it might work something like the difference in focus point between regular film and infrared.

 

[RObert Budding]

Henry Scherer has done careful measurements:

"Up until now the thinking had been that the Nikon and Contax helical thread pitches were different, but this tis is not correct. Looking backward with perfect hindsight its easy to see that the thread pitches had to be the same. If they were different then the case would be who got it right, Nikon or Contax? The answer is that both were right and Zeiss figured out the right pitch to use first. But there must be something that explains the difference between the lenses made for the Nikon and the Contax and it turns out to be very simple. The Nikon is a thinner camera than the Contax. It's actually 0.31 mm thinner."

http://zeisscamera.com/articles_zmsonnar.shtml

http://zeisscamera.com/articles_cnrfdr.shtml

 

[furcafe]

I agree, the fact that the focal lengths for "50mm" lenses are the same in LTM & Nikon RF mount must have made it much easier for them to do a quick "special edition" run of the ZM Sonnar for Nikon RFs for the Japanese market. As much as I would have liked to see it made in Contax RF mount, perhaps the cost of modifying the focal length, etc. would have been prohibitive for the small quantities involved. So, yes, I think it is a matter of economics, especially when you consider the failure of Cosina's line of S & C mount Voigtlander Bessa bodies & lenses.

But, if I remember right, in contrast to Contax, "normal" RF calibration of Leica and Nikon RF are the same, which might have facilitated Zeiss' "port" of the ZM Sonnar to SC mount (no changes in optical part required).

Roland.

 

[RObert Budding]

Well, I read a lot of the referenced threads, and, typical of internet discussions, I'm unconvinced. Mostly a bunch of "I'm right, you're wrong" exchanges without decent illustrations and measurements. Did HS overlook anything? Perhaps, but did anyone contact him to inquire about his methods? Apparently not. But at least he presented his arguement in a coherent and organized fashion.