Capt. E
Established
I have a very nice S3 body with a Nikkor 5cm f1.4, 3.5cm f2.5 and 10.5cm f2.5. That is a complete outfit for the S3 taking full advantage of the marvelous viewfinder. The Nikkor 2.8cm is not that much wider than the 3.5cm and it is a slow f4. I have thought about getting a Voightlander 21 or 24. They are great and come with a nice finder. That is about the only addition I would consider except perhaps another body (S3 or SP).
flavio81
Well-known
I just bought both the 3.5 and 2.5 from eBay this week so someday i'll be able to compare them.
There's a test out there on the web using a digital camera and it shows that if you pixel-peep, at infinity, the 3.5 loses out on the corners. Otherwise contrast and the rest of the image is almost identical to the f2.5 lens.
The same test also includes bokeh testing of the 2.5 vs 3.5 and 1.8 and it shows that the 3.5 has the most neutral bokeh. Attachment included. This latter stuff was the reason i got the f3.5, including also what it seems to be a more recessed front element. This is an important consideration for me.
Attachments
flavio81
Well-known
Note: Consider that the J-12, a good, well manufactured J-12, is calibrated for the Contax flange-focal distance, which is different than the Nikon S flange focal distance. There's a 0.31mm difference, which is a very significant number. (Source)
As you probably know, Nikon used to make those lenses in a "C"-marked version; the very same lenses, but calibrated for Contax cameras.
A proper comparison would be to re-calibrate (reshim/un-shim) your J-12 so it attains precise focus at the film plane with your Nikon S3. Otherwise your J-12 is always technically out of focus. Of course DOF helps mask that problem, but if you want to extract the maximum out of the J-12, you'll need to do that.
I am getting the W-Nikkor 3.5cm f2.5 and f3.5 very soon and will have to re-calibrate them since i plan to use them on my Contax IIa/IIIa cameras. One of my IIa is modified so the Jupiter-12 fits, but I feel that the exposed rear element of the J-12 makes it a slow lens to use out in the field -- it needs a lot of care when taken out or in. The Nikkors have well protected rear elements.
jbielikowski
Jan Bielikowski
I got (heavily used) 35/1.8 for the looks, but it's the rendering wide open that won my heart.
Bingley
Mentor
I don’t use wider lenses than 35mm that much, but I did get the Skopar-S 25/4 and am pleased w/ it. I’ve used it on a Contax IIa w/out any focusing issues. It’s handy for landscapes in some of the deep canyon national parks in the American West, like Zion and Yosemite, and when you’re shooting in cramped surroundings up close.
This has been proven false on this forum multiple times over the years. Focused to infinity, Contax mount lenses of any focal length render an in-focus image when mounted on a Nikon body, and visa-versa. That wouldn't be possible if there was a 0.31mm difference in register (what matters is the register, not the body thickness, though the register does determine body thickness to an extent). Both Nikon RF and Contax RF have a 34.85mm register.
https://www.graphics.cornell.edu/~westin/misc/mounts-by-register.html
flavio81
Well-known
Also this one below. But unfortunately the more detailed threads/comments have been deleted. Maybe Sonnar Brian might like to have another crack at explaining it.
https://www.rangefinderforum.com/node/83369
https://www.rangefinderforum.com/node/83369
Between the Nikon Focus mount and the Contax focus mount: the pitch of the helical is the same, the Nikon rotates a few degrees less than the Contax. The focus throw of the Nikon is less than the Contax, "somewhere around 0.1mm". "AND" the mount and lenses sit a bit differently. The net result:
I shimmed a Nikon S2 mount to take a Zeiss 50/1.5 Sonnar. I had to increase the thickness of the shims by about 0.3mm. Then I calibrated the rangefinder for the Sonnar.
I shimmed a Nikon S2 mount to take a Zeiss 50/1.5 Sonnar. I had to increase the thickness of the shims by about 0.3mm. Then I calibrated the rangefinder for the Sonnar.
How are the images at f1.5 - f2 when the lens is set to infinity?
I dug up the table Cosina provided in the Voigtlander Bessa R2S/C manual. It shows whether the image will be in/out of focus at several focus distance/aperture combinations for a Nikon RF lens mounted on a Contax RF body or a Contax RF lens mounted on a Nikon RF body. Side note, while all lenses in the Voigtlander SC/S lens lineup were designed for Nikon S-mount (states that clearly in the little manual included with each lens), Cosina labelled the 35mm and wider lenses "SC" because DOF "hides" the focus error at all focus distance/aperture combinations when the lenses are mounted on a Contax RF body, but labelled the 50mm and 85mm lenses "S" only, not "SC", because DOF doesn't "hide" the focus error at all distance/aperture combinations. This table shows what you can expect when 50mm and 85mm lenses of one system are mounted on a body of the other system. Infinity is in focus at every aperture (because the register is the same). This wouldn't be possible if there was a 0.31mm difference in "body thickness".
x = out of focus (point of focus is outside the DOF)
O = in focus (point of focus is within the DOF)
Covered by the DOF by F2, and focus shift is towards infinity.
I optimized the focus for 8ft, used a classic optics bench in the Lab. Shimmed the helical until the target was sharp at F1.5 using a 15x loupe, then calibrated the rangefinder. I used "MWS2" precision washers for shims under the focus mount, as stand off to the body. I did this almost 20 years ago, years before Henry's article- the increase in Shim thickness required agreed with what Henry stated. I believe that the optical barrel sits slightly differently in the lens mount between Contax and Nikon, and this requires the extra standoff.
What matters is distance to the image plane from where the lens is mounted on the camera. The focus throw of the Nikon is "about" 0.12mm less than the Contax from 3ft to infinity. I had to increase the mount shims much more than that- to account for differences in construction of the lens mount itself. When I set a Helios-103 to work on a Nikon S-Mount lens I give it 1/2 turn, much more than 0.1mm. It works.
This is with the modified Nikon S2,'C' Nikkor 13.5cm F3.5, wide-open.
This is with the Sonnar 50/1.5 that was used to optimize the camera.
Still have it.
Still have it.
I've only changed the shims on one Nikon body. However- I have changed the shim on many Helios-103 and Menopta 53/1.8 lenses. "They just worked" with increasing the standoff 1/2 turn, which is much more than can be accounted for in the focus throw difference.
Menopta wide-open, adjusted for Nikon S-Mount, on my S3-2000. I used to sell these adjusted lenses for $40, inclusive of shipping for RFF members. Tom A had one. I sold maybe 20 of them? Now- you cannot find them anymore.
The Millenium Nikkor, at F1.8.
The Nikkor is better, has higher contrast. Cannot buy it for $40 though.
Menopta wide-open, adjusted for Nikon S-Mount, on my S3-2000. I used to sell these adjusted lenses for $40, inclusive of shipping for RFF members. Tom A had one. I sold maybe 20 of them? Now- you cannot find them anymore.
The Millenium Nikkor, at F1.8.
The Nikkor is better, has higher contrast. Cannot buy it for $40 though.
keytarjunkie
no longer addicted
Well this has strayed pretty far from the topic. So tired of this 15+ year old debate.
I have a Sony mirrorless camera, a tripod, several nice adapters, and a plethora of Nikkor lenses. If someone is willing to lend or sell me a Contax mount lens, I'll do a proper test at infinity and MFD.
I have a Sony mirrorless camera, a tripod, several nice adapters, and a plethora of Nikkor lenses. If someone is willing to lend or sell me a Contax mount lens, I'll do a proper test at infinity and MFD.
This issue goes back to 1946. There is no debate, Nikon made their cameras with a Rangefinder calibrated for the Leica standard of 51.6mm. Zeiss made the Contax calibrated to 52.4mm.
The problem only matters when using a Contax lens on a Nikon, or an S-Mount lens on a Contax. I've shimmed lenses for both cases, mostly Contax mount to work on Nikons. I've also set a 3.5cm F2.5 Nikkor and 5cm F1.4 Nikkor to work on a Contax.
The problem only matters when using a Contax lens on a Nikon, or an S-Mount lens on a Contax. I've shimmed lenses for both cases, mostly Contax mount to work on Nikons. I've also set a 3.5cm F2.5 Nikkor and 5cm F1.4 Nikkor to work on a Contax.
RObert Budding
D'oh!
A 15+ year old debate is pretty recent. We are, after all, discussing cameras that have been out of production for 60 years!
flavio81
Well-known
I dug up the table Cosina provided in the Voigtlander Bessa R2S/C manual. It shows whether the image will be in/out of focus at several focus distance/aperture combinations for a Nikon RF lens mounted on a Contax RF body or a Contax RF lens mounted on a Nikon RF body. Side note, while all lenses in the Voigtlander SC/S lens lineup were designed for Nikon S-mount (states that clearly in the little manual included with each lens), Cosina labelled the 35mm and wider lenses "SC" because DOF "hides" the focus error at all focus distance/aperture combinations when the lenses are mounted on a Contax RF body, but labelled the 50mm and 85mm lenses "S" only, not "SC", because DOF doesn't "hide" the focus error at all distance/aperture combinations. This table shows what you can expect when 50mm and 85mm lenses of one system are mounted on a body of the other system. Infinity is in focus at every aperture (because the register is the same). This wouldn't be possible if there was a 0.31mm difference in "body thickness".
x = out of focus (point of focus is outside the DOF)
O = in focus (point of focus is within the DOF)
I was looking for this info, many thanks.
Is this table for using Clenses on a S-mount camera, or viceversa?
flavio81
Well-known
This is very interesting info. In the part in bold, i assume you mean this happens for the lenses that use the inner mount (most "50mm" lenses), right?
I find very interesting that the Voigtlander R2C/S leaflet shown here shows perfect infinity focus even with a 50/1.5 or 85/2. This would support the "both cameras have exactly the same lens-flange-to-film-plane distance", as a moderator has stated here.
So far my understanding is:
- Same flange-to-film plane distance, so a lens set to infinity will focus OK at infinity on both Contax and Nikon cameras.
- Different rangefinder calibration, Nikon calibrated for a ~51mm lens and the Contax for a ~52mm lens (can't remember the exact values), so the rangefinder won't really agree with an alien lens, and the difference is more marked at near distances.
- The way to perfectly compensate for this different rangefinder calibration (perfectly = at all distances) is to change the "stand-off" and to modify the focal length of the lens.