Carl Zeiss Jena Prototypes, Experimental, and Transition Lenses,

I actually have one of those 4 13.5cm f4 Sonnars



I remember that! Looked it up in Thiele. Figured since there were TWO made, I was not going to fall into one- so I converted a Contax mount lens to LTM using a J-11 mount. It is a remarkable lens.
 
@dexdog @TenEleven @Sonnar Brian I appreciate the images and further context you provide, though I feel a bit bad because I made a little mistake, writing from such a lens, while meaning of. I'm aware the lens block and thus the images produced are likely identical to the early Contax mount lenses. Either way, now we have both, images from and of the very early experimental LTM lens in the thread. This is rare content, much appreciated.
 
The above images show the portion of the mount that was filed, which I believe was to clear the lens release on the M3. This lens was used as a "regular" lens for a long time.
 
It's so strange that the helical would be visible at infinity. It's a beautiful but also strange lens for sure. The other one two-offs I have seen seemed more "complete" with all moving parts covered. For example analoged's 135 Sonnar looks like a fully finished lens. This is also true for the Biotar 4cm.

Lastly, dexdog, in the pictures I can not see the RF cam, but I assume it has one?
Also it seems the lens would take almost a full revolution to reach 0.9m ... really strange construction.
 
TenEleven, the lens has an RF cam, here is a pic of the lens at infinity. Post #64 above needs to be corrected in that the helical is only visible at close focus setting, not at infinity as I erroneously stated. You are correct that the lens requires almost 360 degree rotation to get from infinity to 0.9m.
 
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Thank you for the clarification!

To be certain the picture you posted above had me very confused as well. Since the infinity mark and the 0.9m mark are both to the right of the distance line I assumed that it was focused just a wee bit short of infinity. But I guess instead it was at the closest focus which goes over infinity again, I assume?

A bit like the Rolleiflex Standard which also required two revolutions of the focus knob to play out to the closest distance.

This is going to be a "nerdy" question and perhaps hard to answer, but is the focus delimited in any way? Or can you just turn until it comes apart - kind of like an Elmar with the screws removed? I am asking because I can not see anything obvious that would delimit the helical travel.

Also as a side-note - the RF cam looks very similar in construction to the Biotar 4cm f/2 cam.
Including the fact that it's painted on the side and then apparently polished down to the required distance (is my assumption anyway). I guess you can do that level of effort for a one or two-off lens.
 
I just unscrewed the optical block out of the focus mount/lens mount. There was a bit of a hang-up when the optical block unthreaded, which kinda scared me given that this was the first time I had ever tried to take it apart! Anyway, I took pics of the lens mount at close-focus and infinity...not the best pics, but you get the idea. There is no delimiting screw, and it appears that the helical in the lens mount bottoms out on the lens mount at infinity
Close focus at 0.9 meters

Infinity focus


Sonnar B, feel free to split the discussion of the 1933 LTM Sonnar into a separate thread to avoid bogarting the 5.8cm Sonnar thread.
 
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We could do a separate thread on just the experimental lenses-
But the Seial Number tie in to the 5.8cm F1.5 is very interesting. Too close to be just coincidence.
 
I just unscrewed the optical block out of the focus mount/lens mount. There was a bit of a hang-up when the optical block unthreaded, which kinda scared me given that this was the first time I had ever tried to take it apart! Anyway, I took pics of the lens mount at close-focus and infinity...not the best pics, but you get the idea. There is no delimiting screw, and it appears that the helical in the lens mount bottoms out on the lens mount at infinity
Close focus at 0.9 meters

Infinity focus


Sonnar B, feel free to split the discussion of the 1933 LTM Sonnar into a separate thread to avoid bogarting the 5.8cm Sonnar thread.
Thank you so much dexdog. That's super interesting. And it basically confirms the hunch that this is a prototype of some sorts.
Also interesting to me: the optical black mounting looks very different from the Contax production Sonnars. Clearly a lot of effort went into this. I mean this is the machine age - someone had to draw and measure these up - probably make some dies etc.... this was a lot of work ... and then .. two lenses. Really strange!

And, yes even after hundreds of lenses I still get a pit in the stomach when a rare lens has a reluctant thread or screw...
However oftentimes there really is not much of a choice unless "unusable shelf-queen" is a choice for you.

Lastly if someone makes a Zeiss oddities thread, I guess we could re-post the info there.
Or just rename this one to Zeiss oddities?
 
I thought that it is widely known that the CZJ Sonnar 5,8cm F/1.5 is a ... not original Carl Zeiss Jena lens.

Hartmut Thiele mentions this lens in his "Fälschungen - Kameras und Objektive" ( there is even an image of the Leica-Sonnar 5,8cm on the books cover) and in "Legenden und Geschichten zur Leica". His books are in German but he provides a list of known Zeiss serials of frauds in there too. He is even mentioning that the CZJ Sonnar 5,5cm and 6cm are frauds too.
 
I thought that it is widely known that the CZJ Sonnar 5,8cm F/1.5 is a ... not original Carl Zeiss Jena lens.

Hartmut Thiele mentions this lens in his "Fälschungen - Kameras und Objektive" ( there is even an image of the Leica-Sonnar 5,8cm on the books cover) and in "Legenden und Geschichten zur Leica". His books are in German but he provides a list of known Zeiss serials of frauds in there too. He is even mentioning that the CZJ Sonnar 5,5cm and 6cm are frauds too.
The thing is though that they are Carl Zeiss Jena lenses.

They were just originally not intended for photographic purposes. But Carl Zeiss Jena still made them. Their open letter even states as much. It was just that a 3rd pary (likely ex-Zeiss engineers) remounted these into a focusing helical and added an aperture mechanism. Was this fraud? Yes. Are these still Carl Zeiss lenses? Also, yes.
 
It is the same issue with the first batches of Jupiter Sonnars. The soviets took almost everything from the Jena factories including parts, lens bodies and glass. They even took engineers and brought them to Kiev. Then they started the Jupiter production. In the beginning they assembled the incomplete lenses and used up all spare parts. Since they started the Jupiter production with the original production machines, with the original engineers and with the original glass one could argue they produced Jena Sonnar lenses. Today it is very difficult to tell an original CZJ Sonnar lens apart from a Kiev-assembled or from an stolen-parts-assembled one. Your best shot is the Thiele Nummernbuch since Mr. Thiele got the production cards from CZJ Saalfeld factory. If there is no production card than chances are high it is an irregular lens.

After the Jupiter production used up all the Schott glass they had to use other glass available in the CCCP. So they did a recalculation of the Sonnar 50mm F1.5 design in 1954. After this they used the new calculated Sonnar design. I would say it was a successful recalculation since it is as good or a little better than the previous wartime design from Bertele. Maybe the used coating improved it over the previous design.
 
It is the same issue with the first batches of Jupiter Sonnars. The soviets took almost everything from the Jena factories including parts, lens bodies and glass. They even took engineers and brought them to Kiev. Then they started the Jupiter production. In the beginning they assembled the incomplete lenses and used up all spare parts. Since they started the Jupiter production with the original production machines, with the original engineers and with the original glass one could argue they produced Jena Sonnar lenses. Today it is very difficult to tell an original CZJ Sonnar lens apart from a Kiev-assembled or from an stolen-parts-assembled one. Your best shot is the Thiele Nummernbuch since Mr. Thiele got the production cards from CZJ Saalfeld factory. If there is no production card than chances are high it is an irregular lens.

After the Jupiter production used up all the Schott glass they had to use other glass available in the CCCP. So they did a recalculation of the Sonnar 50mm F1.5 design in 1954. After this they used the new calculated Sonnar design. I would say it was a successful recalculation since it is as good or a little better than the previous wartime design from Bertele. Maybe the used coating improved it over the previous design.
There are unrecorded details that are just not in the book. In Thiele there are some serial numbers listed with "receipt missing", but are regular production lenses. I've taken apart Wartime lenses, irregular production lenses, ZK Sonnars, and early J-3's. Once they are disassembled, is not too difficult to tell one from another. The serial numbers stamped into the inner parts of the LTM Zeiss lenses is also a good indicator.

The KMZ Jupiter-3 5cm F1.5 V1 is optically better than the recomputed KMZ Jupiter-3 V2. I have samples of both. I have a v1 produced, 1956 SN, I also have v1 J-3's from 1950, 1951, 1952, and 1953. I have 1955 and 1956 V2 Jupiter-3 5cm F1,5: perfect glass. I cherry pick lenses. The v2 shows more field curvature and is not nearly as sharp at the edges. I can speculate the inferior quality is the reason production was transferred to ZOMZ in 1956.

I've seen 4-digit serial numbers on ZK lenses. This is from a 272 block LTM lens. This focus mount relies on a screw through the focus ring as the start/stop focus limit. The J-3 design uses an internal stop screw, much less likely to cause problems.
helical_sn.jpg
 
My irregular production CZJ 5cm F1.5 Sonnar T, SN block 2865xxx and my 1949 ZK Sonnar.

The irregular production Sonnar- a lot of "one-off" quality to the machining, extra holes in the focus ring, Zeiss glass. The rear triplet is smaller diameter than a regular production lens. I have seen several like this. Maybe for a Movie camera mount?

The lens works- but focus is uneven, I worked with it quite a bit trying to get usable for an RFF photographer. In the end: I traded one of my converted Sonnars for it.

RIMG0209.jpgRIMG0211.jpgRIMG0214.jpgRIMG0216.jpgRIMG0217.jpgRIMG0219.jpg

The middle triplet and front element are Zeiss, exact same size and power as regular production lenses. The irregular production lens is missing one aperture blade. The Aperture works fine. The SN puts it as a Kipronar production lens, that SN group is just after the "regular production" Sonnars. It's not a Kipronar, it is a 5cm F1.5 Sonnar. Just not a regular production. More like it was made with what people could find and put together.
 
@Sonnar Brian do the very early ZK Sonnars use the same rangefinder standard as the wartime Zeiss lenses, i.e. 51.6mm? Or do they already have the helicoid movement of the later Jupiters, leading to the known inaccuracies?
 
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