What is this lens ?

[lightfootwillwalkinthecat]

Herstellcr blc Bauart blc 1:6.3 75cm
Its a big lens... front element is 6" across...

I'm thinking of buying it for a future 20x20 wet plate camera I'm going to build... mostly portraits.
I can find any information about this lens at all ????

anything would help :)
This is my first post on this site , cant wait to start delving into all the years of knowledge

Thanks

[ridax]

75cm f/6.3? It probably is an airplane lens. If it is not a telephoto, it most probably would cover 20x20" OK. But it probably is quite heavy. An East German 750mm f/9 CZJ process Apo-Tessar would cover, too, and in an Aluminum barrel, it would be much lighter in weight.

Besides, a number of (but luckily not all of) the aerial survey lenses are chromatically corrected for green to near infrared but not to the blue. It's hard to tell if the one you mention is one of those or not before you try it out. And if it is, it would make really soft images with wetplate.

But all the above are just speculations. A picture of the lens would help.

[Dan Fromm]

"hersteller blc" means "manufacturer Zeiss military department." It is a WWII German code. bauart means type.

Yes, aerial camera lens.

[Mark Sawyer]

Check the actual focal length to see if it's a telephoto or not. As Ridax suggested, a telephoto lens will cover much less, and most of the longer aerial lenses were telephotos.

[Dan Fromm]

Per the VM, which isn't always right, it is most likely a Telikon, made for a camera that shot 30x30 cm and covers 31 degrees, which is tight for 30x30.

OP, if you want more certainty, post the serial number and if you're lucky someone who has Theile on Zeiss production records may be able to give you more information. Hint: pester David Lindquist.

[David Lindquist]

Thank you Dan:)

Going out to dinner tonight but will be happy to look it up when I get a chance; I'm on Pacific Daylight Time here.

I consider Hartmut Thiele's work to be an extremely valuable resource, but to be forewarned, there are some gaps. Very understandable when considering he looked at archives that covered about 130 years and went through two world wars.

David

[ridax]

Per the VM, which isn't always right, it is most likely a Telikon, made for a camera that shot 30x30 cm and covers 31 degrees, which is tight for 30x30.

If it really is a Telikon - I've owned its exact Soviet copy put in production in about 1942, the 750mm f/6.3 Telemar. It needs about two times less a bellows draw than a non-telephoto lens of the same focal length; it does not cover more than its nominal 30x30cm at any f-stops, and it is huge with about 12" long barrel and weighs a lot. And yes that is one of those aerial lenses that aren't corrected in the blue (though the original Telikon may be different in this aspect). I've got rid of it....

[ridax]

Besides, my 750mm f/6.3 Telemar was really yellowish in its transmission. It was made to be used with deep yellow to red filters from the start so it did not need any blue transmission at all and was coated accordingly. And all the glass types it was made of were flints - namely, heavy flints and barite flints, which aren't very transparent for the violet rays. And as the lens was big, its elements were thick enough to make the glass yellowishness quite visible. The lens was fast for panchromatic and paninfra emulsions only.

German coating was definitely better, and German glass probably had less impurities and thus less yellowishness but still I doubt the original Telikon could be considered a fast lens for blue-sensitive emulsions either. Chances are, a f/9 process lens would allow for the same or even less exposure times with wetplate.

[lightfootwillwalkinthecat]

amazing information guys... thank you soooo much....
I'm in the early stages of planning this 20X20 build... ( I haven't shot large format in over 20 years :)
is there any lens you could recommend ( $500- $800 range ) that would cover a 20" x 20" with no movements and head and shoulder type portraits, so no infinity coverage needed... thanks