Carl Zeiss Sonnar T* 50mm F1.5 Limited Edition Nikon RF Mt

[ernesto]

I have just read this article:
http://www.zeisscamera.com/articles_zmsonnar.shtml
That says the cosina new Sonnar http://www.cosina.co.jp/seihin/co/s-50limited/index.html
is wrong labeled as S (nikon mount) but it is in fact C (contax mount) lens.
I wonder if any user have noted this in practice...





Ernesto

 

[Costo Kim]

1. If a lens made for the Nikon S, such as a 1960's Nikkor 50 mm f1.4 is to be used on a Contax it needs to be adjusted to move the lens cartridge deeper into the mount and the amount of this adjustment must be 0.31 mm. This is accomplished by removing spacer washers.

2. If a lens made for the Contax , such as a 1960's Carl Zeiss 50mm f1.5 Sonnar, is to be used on the Nikon, the lens needs to be adjusted so that the lens is moved 0.31mm further out of the mount.

Henry is wrong here
1960's Nikkor 50 mm f1.4 has focal lenth 50 mm BUT 1960's Carl Zeiss 50mm f1.5 Sonnar is actually 53 mm
this is the main reason why new C-Sonnar is labelled as Nikon-S mount lens - Nikon-S' cameras helicoid is designed for 50mm lenses (Contax-RF mount is for 53 mm lenses)

 

[steamer]

I was kind of excited about this article then I realized it was just the famous repair guy's delirious ramblings. This whole thing has already been dealt with in other threads.

 

[PeterV]

I actually asked the Zeiss guys and they answered that the new Sonnar is most definitely designed for Nikon S, not for Zeiss Contax (which kept me from ordering one).

Peter

 

[furcafe]

ernesto, Mr. Scherer is building upon his earlier error, which Brian Sweeney explained to you here:

http://www.rangefinderforum.com/forums/showthread.php?t=59603

 

[Tom A]

I did some shooting with a Contax IIa and the SC-C Sonnar 50f1.5 a couple of days ago. I actually switched lenses around between a R2S(Nikon Rf mount Bessa) and the Conatx IIa.
I tried to get an idea if there was any significant shift when using the SC lens on the IIa and the venerable Sonnar 50f1.5 on the R2S.
I could not really see any difference! OK, I wasn't shooting testcharts or brickwalls, but used them as I would use it in "real life".
My conclusion is that either lens would work on the cameras. So, I would not be using them for copy work, but who copies at f1.5 anyway!
I did put some 40+ shots from the test on a set on our Flickr site. I know that computer screens are not ideal for judging optics, but looking at the negatives, I would have no problem blowing them up to 11x14 or even 16x20 if I wanted too.
There is actually not that much difference between an early 50f1.5 Sonnar and the latest SC Sonnar. The latter has a bit more contrast and possibly more resolution, but in bl/w - either one would do fine!

 

[summilux]

maybe the difference between the nikon and contax has made the focus shift less on contax than nikon?
anyway the sonnar is plentiful in M mount nowadays.

 

[nzeeman]

thanks tom. i think that myths about incompatibility of nikon and contax and focus shifts in sonnar are finally - busted. 😀

 

[jsuominen]

I could not really see any difference! OK, I wasn't shooting testcharts or brickwalls, but used them as I would use it in "real life".
My conclusion is that either lens would work on the cameras. So, I would not be using them for copy work, but who copies at f1.5 anyway!

Tom, this is the same conclusion what I was told, when I asked it here:
http://www.rangefinderforum.com/forums/showpost.php?p=874949&postcount=54

I'll do some "testing" with my own Contax IIa and S-mount Sonnar 50/1.5 later. At least C-mount Menopta 53/1.8 showed some focus errors on S-mount Bessa R2S:
http://www.flickr.com/photos/jsuominen/738653625/

 

[summilux]

Of course it's a Nikon-designed lens, see :

http://www.rangefinderforum.com/forums/showthread.php?t=57560

Herr Scherer is a Contax RF repairer and he seems to have impulsively bought some quantities of that lens for further retail sales.

Since his customers are classic Contax cameras users, to sell his Nikon RF-designed C-Sonnar 50/1.5 T* surplus he now has to convince them that the lens is the result of a major goof at the factory and that it's actually a Contax RF-designed standard lens which (according to his schmitz-schmutz) is about to become a collectible because now that Mr Kobayashi's ingeneers have discovered their mistake there will be a second production batch and this one will turn out to be of some actual Nikon RF-designed lenses.

Pass the nuts bag, and have fun.

he did not say this lens will be collectible, he said zeiss refused to confirm how many are actually made, so much for what limited means in this context. besides, tons of ebay sellers, from japan or europe, are now selling this lens.

and believe it or not, he is using Collimator, not his eyes to test the lens.

 

[jsuominen]

zeiss refused to confirm how many are actually made, so much for what limited means in this context.

Yep, you're right. Zeiss didn't tell it me either when I asked about it. But if I have serial #15715012 and Tom has #15715294, it looks like they might have made them 300 pieces as Tom wrote earlier (if all numbers begin 15715***). I wonder who owns *****001 or *****300? 🙂

 

[ernesto]

Well, I am surprised to read so many attacks to the person, instead of considering the experiment.
Thanks Tom for your tests!

Ernesto

 

[ernesto]

Perhaps there is no practical diference between Nikon and Contax mounts and both manufacturers normal lens, if we consider the limits of today´s technology.

All practical tests seems to confirm that both systems could be interchangeble with good results.

All theoretical analisys confirms that the two mounts are diferent, assuming that these diferences are due to a diference in focal length from 51 to 53.

But have you wondered why Zeiss do not provide information on the subject? Have you wondered why neither Nikon did it?
There is a good answer for this:

The most sophisticated human technology cannot guarantee that a lens is really a 50mm. The variation from one lens to another in the same production line can be as wide as 49 to 55mm of effective focal length, and there is no way to know the specific focal length unless you made measurements. The average focal length in the production line is kept near 50mm, but this is only the average. Only a small quantity of lens are really as the average.

Perhaps it is true that the theoretical normal focal length for contax was 53 and the same for nikon being 51, but this is only theory. Both manufacturers will produce random effective focal length, and their tolerances are higher than the alleged diference betwen S and C mounts.

This is also the reason for Zeiss and Nikon for not to clarify things, since by doing so they will be telling us their technological limits, and that wouldn´t be good for their accuracy reputation.

Mr Scherer´s approach is NOT theoretical, but practical, and it is really the only way to know reality.
We were educated to trust mathematics blindly, but our world is full of random imperfections, and we must learn to live with them, and put maths in the place it deserves.
It is totally nonsense to discuss if a normal lens should be 50mm or 51mm if we have no way to produce them in the line with that accuracy!

We must be carefull and not disqualify someone just because his approach is not the same as ours. You all are right, just that eachone is watching the subject from a diferent viewpoint.

If I say that I am 1.87m tall I am right but perhaps I will be totally wrong because I ommited the milimeters, and if I do the measurements in the winter they will be diferent from the summer, or if I do the measurements just after getting up, it will be diferent from the data obtained at the evening.

Let´s trust what we experience: the images made with the lens, rather than in theoretical mathematics!

Ernesto

 

[nzeeman]

Perhaps there is no practical diference between Nikon and Contax mounts and both manufacturers normal lens, if we consider the limits of today´s technology.

All practical tests seems to confirm that both systems could be interchangeble with good results.

All theoretical analisys confirms that the two mounts are diferent, assuming that these diferences are due to a diference in focal length from 51 to 53.

But have you wondered why Zeiss do not provide information on the subject? Have you wondered why neither Nikon did it?
There is a good answer for this:

The most sophisticated human technology cannot guarantee that a lens is really a 50mm. The variation from one lens to another in the same production line can be as wide as 49 to 55mm of effective focal length, and there is no way to know the specific focal length unless you made measurements. The average focal length in the production line is kept near 50mm, but this is only the average. Only a small quantity of lens are really as the average.

Perhaps it is true that the theoretical normal focal length for contax was 53 and the same for nikon being 51, but this is only theory. Both manufacturers will produce random effective focal length, and their tolerances are higher than the alleged diference betwen S and C mounts.

This is also the reason for Zeiss and Nikon for not to clarify things, since by doing so they will be telling us their technological limits, and that wouldn´t be good for their accuracy reputation.

Mr Scherer´s approach is NOT theoretical, but practical, and it is really the only way to know reality.
We were educated to trust mathematics blindly, but our world is full of random imperfections, and we must learn to live with them, and put maths in the place it deserves.
It is totally nonsense to discuss if a normal lens should be 50mm or 51mm if we have no way to produce them in the line with that accuracy!

We must be carefull and not disqualify someone just because his approach is not the same as ours. You all are right, just that eachone is watching the subject from a diferent viewpoint.

If I say that I am 1.87m tall I am right but perhaps I will be totally wrong because I ommited the milimeters, and if I do the measurements in the winter they will be diferent from the summer, or if I do the measurements just after getting up, it will be diferent from the data obtained at the evening.

Let´s trust what we experience: the images made with the lens, rather than in theoretical mathematics!

Ernesto

totally agree with this. thanks.

 

[Tom A]

You cant take pictures with theories! I use lenses and if it meets my criterias of sharpness, contrast and tonality - it is a good lens, if not, it is a lens that I am not interested in, but that does not mean that someone else would not like it!
As for "real" focal length - Leica had quite substantial variations on FL and used to engrave a code on the side of their 50's to identify it,
All of the DR Summicrons came from batches that were 51.9mm FL - the rest could vary by a mm or more.

 

[RObert Budding]

Yes, it's frustrating how these 'discussions' degrade into name calling. I suppose it's easier than formulating a carefully considered argument and supporting it with facts.

 

[ernesto]

If you look carefully, you will notice that the distance between both curves are diferent depending on which point you look at. At the data point number 1, they are closer, compared to data point 15 where they are more separated. Perhaps if we change the scale of the graph (attached) it would be more noticeable...
The two black reference measurement are identical, and they are 0.31mm tall.
Note that the lines are more separated at data point 15, so in fact you are right: the contax line is longer.

The first distance is 0.31 , and the last is 041, but there is an optical illusion that makes the trick.

Ernesto

 

[ernesto]

Well, this graph does not show rotations, it only shows distances from the mount to film plane, for each distance marked in the mount.
In other words, data point 15 is comparing Nikon mount rotated at 260 degrees, to the contax mount rotated at 270 degrees, which are marked 3 feet in both mounts.
So the diference between 0.31mm and 0.41mm = 0.11mm correspond to the extra 10 degrees in the contax mount.
The contax mount moves the lens only 3.36mm through its axis, after rotating 270 degrees, meanwhile the nikon mount moves 3.35mm after rotating 260 degrees from infinity to 3 f.
The diference is in fact really small. Inded smaller than the possible human error at focusing the subject!

Ernesto

 

[ZeissFan]

I've just processed a roll of Rollei ATP. Half of the shots were with the 2008 limited edition f/1.5 C-Sonnar and half with the f/1.5 Sonnar from the 1950s.

There's been much talk about the differences in the 50mm focal lengths between the Nikon S and the Zeiss Ikon Contax.

What I've found in my situation supports what Tom says: In real-world use, the C-Sonnar works fine with either camera.

Shots taken at f/1.5 with the C-Sonnar were certainly acceptable. But I want to do further testing before I make any further statements.

This surprised me, because in theory, the two systems shouldn't be able to share any lenses.

 

[Tom A]

I just posetd 10 shots on our Flickr site, done with a Bessa R2S of my usual test subject, a chair and sticky post-it notes! I used the SC Sonnar 50f1.5, an old Contax IIa Sonnar 50f1,5 and the Millenium Nikkor SC 50f1.5 (and i managed to squeeze in a shot with a Nokton 50f1.5 SC before the end of the roll too). Go to our Flickr Site and use the tag "Sonnarism" and they should show up. They are done at f1.5,f5.6 and f16.
Later I will reverse the process and load up the Contax IIa and use the same lenses on that one and I might even try them on the Kiev 4 that a friend gave me last Sunday. I just have to figureout hpw to fix the rewind function on it.