CZJ Biotar 5.8cm f2 LTM mount - HELP!

[MalvadoPhD]

Hello my fellow rangefinder fans! I’m here today because I’m very curious about a lens that I found, I know my way around Leica bayonet mount optics but I know almost nothing about LTM ones...

The lens in question is marked as a Carl Zeiss Jena Biotar 5.8cm, f2. The serial number is 3337853. It has 17 blades in the diaphragm, by the way.

I’ve found some information about the Exakta and M42 mount version, but this one I have happens to have a LTM mount and I can’t find any info (or even photos) of this kind of lens with this particular mount.

Not eBay or Google have any results about it, the only site I found with a similar lens is a ColectiBlend listing, which doesn’t tells me anything but at least shows an identical lens to mine:

http://collectiblend.com/Lenses/Zeiss,-Carl-Jena/58mm-f2-Biotar-T-(M39).html

So, does somebody know something concrete about this Biotar? Is it a factory mount? Aftermarket maybe? Is it rare? How much would it cost in the current market?

Bellow I’ll upload some photos, if you need any particular detail ask and I’ll upload a photo of it. 🙂

Thanks a lot for any help! 🙂

 

[raid]

It is most likely a custom adapted lenses by someone, but I don't know whether it could have been factory adapted or not.

 

[johannielscom]

Looking at it, I'd say the front part and the wide rear mount part are of different origin. They have different color and structure of paint, even though they appear to have been made from the same alloy.

The tab that links the optical block to the rangefinder cam looks like the tabs that were used on other models of lenses, with the 45º angled sides. I used to have Komura and Acall lenses from the 1950s or 1960s that used the exact same design to link the optical block to the rangefinder cam in the camera.

The large screws on the rear mount tube seem very out of style. Very unlike a Zeiss approach in their color, although they are a very flush fit.

I would be most interested to know whether it registers correctly with a Leica rangefinder throughout the focus range? In other words, is infinity correctly focused and is close-up focus also correct? If that is the case, then there is a helicoid in the lens that is made to agree with on the one hand a Leica camera, and on the other hand the non-standard focal length of a 58mm lens. The presence of a helicoid like that would rule out any hack job imho. Because that takes some serious designing and manufacturing.


EDIT: Thiele says:
Karte 1089, Biotar, 5,8cm, calculated 19.10.1936, 1,000 pcs., 3.337.301 to 3.338.300, M42, batch completed 10.11.1948.

So that would signal an M42 lens, adapted to Leica M39. BUT: if it registers correctly on a Leica, it may have been a conversion done by a moonlighting Zeiss employe? I'd be interested to know whether it works correctly with the rangefinder on a Leica!

 

[raid]

I have a Zeiss 5cm/2 that has a ltm mount. It seems to be an Elmar shell that was adapted to the optical block. It focuses correctly at both ends.

 

[johannielscom]

I have a Zeiss 5cm/2 that has a ltm mount. It seems to be an Elmar shell that was adapted to the optical block. It focuses correctly at both ends.

But 50mm is close enough to have close-up focus spot on and have infinity covered by the increased depth of field.
For 58mm, that might become an issue...

I wish Brian were here, he'd know whether 58mm on a standard Leica helicoid thread would mess infinity up...

 

[raid]

Brian would have said (most likely) that he would have to take the lens apart to decide such an issue.

 

[analoged]

Always thought a black paint 5.8cm Biotar would be great in Leica Thread Mount, and there it is!

 

[raid]

I have a Russian copy of a Biotar 5.8cm (Helios 44) ... in some mount. Did it also come in Contax mount? I need check out which mount my lens has.

 

[teddy]

I have this lens in Exakta mount. Pulled it apart to fix focusing - damn hard to put it back - but I did it and now the helical focuses perfectly. One thing that I can think of is that it would be hard to know how well it focuses in LTM unless you did some focusing test shots. Focusing may not be exact, it all depends on the mount flange distance, rangefinder cam and helical pitch? Sounds like a nightmare and a compromise. Specially for a lens I think was more designed for close range photography.

 

[raid]

On the M240 with LiveView, focusing will be a piece of cake.

 

[teddy]

If that is the case, then there is a helicoid in the lens that is made to agree with on the one hand a Leica camera, and on the other hand the non-standard focal length of a 58mm lens. The presence of a helicoid like that would rule out any hack job imho. Because that takes some serious designing and manufacturing.

The helicoid on this lens is damn, damn hard to put back together. It is complicated. Totally agree with your question. I would say it is a mismatch. But who knows - making some test shots - never know until it is done.

 

[David Hughes]

During the early days of Leica and Contax a lot of other makers' lenses were available. F'instance Dallmeyer offered their lenses "for any miniature camera" in an advert I've seen in a December 1936 magazine.

Then the war added many cobbled together cameras to the confusion of us all these days. And, of course, the USSR did some work fitting CZ clones into Leitz mounts and so on.

So the experience and machinery were there for this lens to be made by someone. We just have to find out who did it...

The rear end, where it engages with the RF, reminds me of one I've seen from a well known maker but I cannot for the life of me think of their name...

Regards, David

 

[MalvadoPhD]

Thanks a lot to everyone for your help! I sadly don't own any LTM mount camera and not even an M mount anymore, but I did mounted the lens on a friend's M3 with the corresponding LTM adapter, and it did seem to link correctly to the rangefinder cam, it moved correctly from infinity to close focus. Sadly we didn't had time to test it with film, which after reading your comments seems to be a must in a mystery lens like this one.

I'll try to test it with film ASAP! I assume that it would be better to use a native LTM mount camera, correct? Not an M mount with an adapter ring.

Thanks again for all your help! 😀

 

[johannielscom]

Thanks a lot to everyone for your help!

...

I'll try to test it with film ASAP! I assume that it would be better to use a native LTM mount camera, correct? Not an M mount with an adapter ring.

Thanks again for all your help! 😀

Hey!
an LTM camera of an M camera with a known correct adapter, both would do the job just fine!

Hoping you'll report back here in a while, eager to find out if these conversions are correctly focusing!
Thanks for sharing, very interesting!

 

[JB-Dancer]

Carl Zeiss Jena did make 46 LTM Biotar lenses in the 1930/40's but they were 5cm f1.4 Biotars.
Serial no.2253931 to 2253950 (20 lenses) were completed 01/02/1938.
Serial no.2375379....................( 1 lens ) was completed 13/05/1938.
Serial no.2651111 to 2651115 ( 5 lenses ) were completed 30/05/1940 (coated).
Serial no.2651116 to 2651135 (20 lenses) were completed 30/05/1940.

Lens Serial no.2375379 was sold at Westlicht Auctions some years ago and records of this lens might be in their auction archives.I will see if I can find a photo of it.

LATER EDIT:-
I found the original listing with photo of the lens (see below)

Please see:-Camera Auction 19 - May 2011 Lot No.216.
http://www.westlicht-auction.com/index.php?id=418&L=1


216. Carl Zeiss Jena Biotar 1,4/5cm T
very rare original rangefinder coupled Biotar for ...
Condition: B+
Year: 1938
Serial No.: 2375379
Hammer price (Incl. buyer's premium)
€ 3.360
Estimate
€ 2000 - 2500