Zeiss 5cm f2

The original Zeiss Contax and Nikon S mounts are mechanically the same
So you can mount the lenses on either

not correct --> The flange to film plane distance is slightly different though
correct --> This means rangefinder calibration/accuracy is not perfect with cross mounted lenses

Depth of field covers this up for 35mm lenses and wider

50 and 85 are going to have issues at one end of the focus range
They can be successfully used with attention to this above differences

I never do this though - it's simpler to get a Contax body or a Amedeo Contax-> M adapter
 
The difference is not the flange to film plane, but the pitch of the built-in helicoid. Contax rotates 274 degrees, Nikon only 270 degrees. Should not be a problem except at close distances and large apertures.
 
There's a lot of ambiguous info about Nikon S vs Contax

I take back my comment re the flange distance


here's some "research" I wrote up in 2008

I think I figured out the difference between Nikon and Contax focusing, and afterwards I found a posting or 2 that seem to agree

On the Nikon site http://imaging.nikon.com/history/chronicle/rhnc09s-e/ - they mention that the actual focal length of the Nikon 50mm was the Leica Standard 51.6mm
and the Zeiss Sonnar was 52.3mm, that is to say the 50mm designation is more customary than meant to be exact. Nikon may have made lenses for Leica apparently and didn't redesign the optics

There is an optical formula 1/S1 + 1/S2 = 1/f ( http://en.wikipedia.org/wiki/Focal_length ) , where S1= distance from front nodal point, and S2 = distance from rear nodal point, so that if the film plane is at the rear nodal point distance the image will be "in focus"

I then built a spreadsheet varying the distance from effective infinity to 0.5 meters, and for any focal length and distance to subject , you can see how far the rear nodal needs to be
from the film plane for that distance to subject to be in focus

What I found is that , while you can position either lens so that inifinity is in focus on the Nikon, or close up is in focus, you can't do both with the same helical and 2 different focal lengths

in fact, with the longer focal length, the close focus distance of the rear nodal point to the film plane is greater than a slightly shorter focal length

What this means is that at some level the offsets of distance markings on the Nkon/Contax barrels (you have to turn the Contax more degrees to focus at the same close up distances as the Nikon) make sense, to close focus the Sonnar, you need to extend the lens just a wee bit more than you would for the presumably shorter focal length Nikon Lens.

The helicoid pitch is the same, i.e if you move the barrel the same degrees, the lens will move the distance forward/backward on each mount

I also know that the lenses have a certain depth of field, probably on both rear focus plane and subject side, so within reason you can use some lenses not specifically designed for the camera with
good results

the focusing helical and rangefinder are obviously linked, and with other than 50 mm lens, the in camera helical will not move the lens the correct distances to be in focus, so the external mount lenses have their own built in helicals which step up or down the focusing travel to the needs of the specific lens

Since this is my first day as an optical engineer - I should probably stop here :)
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wes loder said:
The difference is not the flange to film plane, but the pitch of the built-in helicoid. Contax rotates 274 degrees, Nikon only 270 degrees. Should not be a problem except at close distances and large apertures.
Click to expand...
 
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The depth from the external mount flanges to the focal plane is the same on both the Contax and Nikon RF. I have used a Panflex with a 50cm Fernobjektiv on a Nikon with no problem with focus. I have also used a Zeiss microflex with a Nikon for photomicrography with no focus issues. Nikon sold their own microflex for use on either a Nikon RF or Contax. The original P copy stand can be used with either a Nikon or Contax. So, the distance of the external mount is not the issue. You should be able to mount either a 135mm Sonnar or 135mm Nikkor or either camera and get sharp results at infinity.
Measured depth of the internal mount of Contax and Nikon also appear to be the same when set at infinity. The helicoid pitch cannot be the same if it takes 274 degrees of turn to go from infinity to three feet with the Contax, but only 270 degrees for the Nikon to cover the same distance. The Contax not only turns farther, but is farther out at every point on the distance scale. Is this due to a difference of focal length of barely over half a millimeter? I don't think so.
Supposed differences in focal length are often cited as the reason for the difference in pitch. I am not sure about that. Lens manufacturers did not have enough control of finished focal lengths to match to a tenth of a millimeter. The only tests that I have seen that actually compared Zeiss to Nikkor normal lenses had the sample Nikkors testing at 52.05mm and 51.92mm. A comparison Sonnar tested at 52.07mm. That is so close a difference as to be meaningless.
Later Nikkors may actually match into the 51.6 length, but that is still only a difference of point seven.
But to return to the original question. Why would you want to use a 5cm Sonnar on a Nikon RF? The Nikkors are sonnar designs, similar to their matching Zeiss models. They yield similar effects. The only gain might be if you really wanted a collapsible lens, but most of the collapsible f2 Sonnars were uncoated and that's no gain.
 
you can turn a screw 270 or 274 degrees, the "helical" is the same in these 2 cases because it's only a single screw, the screw will rise or fall a different distance in each case. the difference is the degrees of rotation allowed

wes loder said:
The depth from the external mount flanges to the focal plane is the same on both the Contax and Nikon RF. I have used a Panflex with a 50cm Fernobjektiv on a Nikon with no problem with focus. I have also used a Zeiss microflex with a Nikon for photomicrography with no focus issues. Nikon sold their own microflex for use on either a Nikon RF or Contax. The original P copy stand can be used with either a Nikon or Contax. So, the distance of the external mount is not the issue. You should be able to mount either a 135mm Sonnar or 135mm Nikkor or either camera and get sharp results at infinity.
Measured depth of the internal mount of Contax and Nikon also appear to be the same when set at infinity. The helicoid pitch cannot be the same if it takes 274 degrees of turn to go from infinity to three feet with the Contax, but only 270 degrees for the Nikon to cover the same distance. The Contax not only turns farther, but is farther out at every point on the distance scale. Is this due to a difference of focal length of barely over half a millimeter? I don't think so.
Supposed differences in focal length are often cited as the reason for the difference in pitch. I am not sure about that. Lens manufacturers did not have enough control of finished focal lengths to match to a tenth of a millimeter. The only tests that I have seen that actually compared Zeiss to Nikkor normal lenses had the sample Nikkors testing at 52.05mm and 51.92mm. A comparison Sonnar tested at 52.07mm. That is so close a difference as to be meaningless.
Later Nikkors may actually match into the 51.6 length, but that is still only a difference of point seven.
But to return to the original question. Why would you want to use a 5cm Sonnar on a Nikon RF? The Nikkors are sonnar designs, similar to their matching Zeiss models. They yield similar effects. The only gain might be if you really wanted a collapsible lens, but most of the collapsible f2 Sonnars were uncoated and that's no gain.
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Apologies to the OP for hijacking the original thread - what we agree on, is that there is a difference and you're probably better off using nikon on nikon and Zeiss on Contax ( Nikon did manufacture "C" versions of the 8.5cm and 10.5cm with external mounts for problem free use on Contax)

The thing I love about RFF, is that we can take something that was argued about 65 years ago, and continue the argument ad infinitum :)
 
I love RFF! Where else could you read a thread like this :D I think we're never going to know the full story about the differences between the Nikon RF and old Contax RF mounts, but speculation is harmless enough.

Fraser said:
I've always liked the look of Carl zeiss Jena 5cm f2 anyone use this on their Nikon rf will it work?
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With a perfectly calibrated Nikon RF body and Contax mount Zeiss lens, infinity will be fine at all apertures but the lens will increasingly back focus as you focus closer to about 10cm back focus at the minimum focus distance of the camera. Stopping the lens down will help cover the focus error. If you can live with that, you'll be fine. The body and lens may also be not quite perfect factory spec but within tolerance in a way that stacks in your favour. Can only try it and see.

This link below is worth checking. The photos are pretty clear, but Google translate from Korean to English helps too. Park compares a Millennium Nikkor with a CZ Tessar, and show that the focus error of the Tessar on the Nikon RF body at minimum focus distance is about 10cm of back focus.

http://sangin1122.tistory.com/entry/Ground-glass-for-lens-shimming
 
Contax / nikon

Contax / nikon

I've posted this before
Leitz started as a microscope manufacturer
Microscopes are an English standard of 26 threads per inch .
Japanese manufacturers assumed the Leica was based metric
25.4 threads per inch .
Enough to cause the error at close focus .
 
The difference between Contax and Nikon S body is of 0.09mm in the distance from the bayonet mount and the focal plane, I have lost the count of the adapters I have made, may be more of 2000, and when a adapter is out of tolerances +/- 0.03mm, I simply trow out it.

The helical pitch can't be considered as a difference between both cameras, I make the standard adapter with a pitch of 4.5mm and the dedicated adapter for 50mm with a pitch of 6mm, the first focus from infinite to 0.9m in around 270 degrees, the second in around 200 degrees.

The more complex problem is the real focal distance of the Sonnar and Nikon S, 50mm, lenses, the Sonnar is near 52.5mm, and for to compensate it, the edge that push the rangefinder cam on the Leica body is machined in a kind of ramp, in this manner, when the helical move forward 3.375mm in a 270 degrees turn, the rangefinder cam move only around 3.31mm.

This compensation is critical for a correct focus at close distance, my dedicated 50mm adapter can focus up to 0.67cm.

In a adapter with lineal movement of helical and cam, the arm of the rangefinder mechanism of the Leica body can be adjusted making it a bit more long, the effect will be the same, but in detriment of the use of 50mm Leica lenses.
 
jonmanjiro said:
With a perfectly calibrated Nikon RF body and Contax mount Zeiss lens, infinity will be fine at all apertures but the lens will increasingly back focus as you focus closer to about 10cm back focus at the minimum focus distance of the camera. Stopping the lens down will help cover the focus error. If you can live with that, you'll be fine. The body and lens may also be not quite perfect factory spec but within tolerance in a way that stacks in your favour. Can only try it and see.
Click to expand...
+1

Recently I found a sparkling prewar collapsible CZJ Sonnar 5cm f/2. I was in need of another 50 like a hole in the head but I bought it (for $90.-) because the front element was the cleanest I had seen on a collapsible Sonnar ever (and the collapsible feature is something I like).

Up to f/2.8 and at all focusing distances, the photos are razor sharp with no focusing error that I can see with either my Nikon S3 or my Contax IIa...

I have shot one routine test pic at f/2 with the Nikon body and the focus really looks to be spot on. So I guess that all the stuff which I own might slightly be a bit out of factory specs and that, yes, everything stacks in my favour at the end of the day.

Nice find, then. ;)
 
Well, We need a test.

I did head to head test to give some more information for this argument. I Used SONY A7 with Contax to E-mount adapter, Micro-Nikkor 5cm F3.5 and Rigid tessar 50mm F3.5. Take a look!


272A3A35574063120373F7


Micro-Nikkor 5cm F3.5 / Rigid tessar 50mm F3.5

2134423857406340238F1F


Micro-Nikkor 5cm F3.5 at Close focus 90cm. (razor sharp, this is my favorite Nikon gear of all!)


244F5A38574063450354A6


Rigid tessar 50mm F3.5 at Close focus 0.9m. (actuall focused around 93~94cm), as I described on the link that Jon mentioned above, there is back focus but 3~4cm. (not 10cm, Jon I'm sorry for my bad old article)


The important thing is here, infinite focus. take a closer look on coming photos.


254CC73857406342060596


Micro-Nikkor 5cm F3.5 at infinite focuse. focused on center of image.



214A54385740634709ACEB


Rigid tessar 50mm F3.5 at infinite focuse, but focused on 10~15m front focus.



242C26385740634321F0AD


Micro-Nikkor 5cm F3.5, Enlarged image of red box the actual focus.

222E1238574063492AA35C


Rigid tessar 50mm F3.5, Enlarged image of red box the actual focus.


Focus problem also exist on infinite focus. This means If you collimate zeiss sonnar for your Nikon RF, You can use perfectly on the gear! Collimation is quite simple.


Here are full size resolution images.
http://sangin1122.tistory.com/entry/nikoncontaxcompatibility
 
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