odd wartime zeiss jena T biogon in later j12 mount

[enasniearth]

i purchased this lens on a chance . after much online research i think it may be an original wartime T biogon at some point mounted in a late black jupiter alloy barrel . the serial number 2712994 is proper for the time period . rear rim has 712994 as is correct , inside lens next to aperature is in pencil 994. lens has light lavender coatings . all the engraveing on the rim - type font size orientation all match others i have seen or located online . so i am asking for help and possibly information .

[enasniearth]

had trouble with loading the photos so now they are posted

[Brian]

I suspect you are correct: a wartime German Biogon in a later J-12 mount. I've done this with the 5cm f2 and F1.5 German lenses, made then into LTM using J-3 mounts.

It did not work with a J-9: threads were the same, but taper of the optics module changed.

The stamped numbers on the rear module are consistent with those that I've seen on genuine German Zeiss Lenses. I think that is a Wartime lens that you have!

[enasniearth]

thanks brian ,

does anyone have the delivery information for this lens ?
any help would be great .
i had another wartime biogon several years ago the first 3 numbers were the same however i can not remember the complete serial number.

[Brian]

It looks to be early wartime, from ~1942.

From a thread on Photo.net
2,678,326-2,790,346 112,020 1942

http://photo.net/large-format-photography-forum/00AAam

I've seen multiple SN lists vary slightly. Figure early 1940s.

[dexdog]

Hartmut Thiele's book shows the lens as one of a batch of 2000 Biogons completed 18 March 1943. Interestingly, it also shows that 400 lenses of this batch were made in Leica mount.

[photovdz]

indeed 2714446 is a LTM biogon ;-)