Mystery Carl Zeiss Lens - Anyone know what this is?

[photos.on.film]

Hello friends, I am an amateur photographer and I came accross this lens at at auction.

It has the words 'CARL ZEISS JENA' rather crudely engraved along with serial number 227780. It has no other information. I do not know what focal length it is. Aperture goes from f/4.5 to f/32. The shutter built goes from 1s to 1/150s. It has another serial number 371939 along with the letters D.R.G.M. It also has a logo that reads 'DF' or 'FD' (one letter is on top of the other). The shutter button looks like a metal pin with a polished metal ball head.

Please could anyone shed anymore light on this lens?

Thank you!

200200200201

[Andrew Plume]

This looks as being one and the same lens in last week's Flint's Auction - hope you didn't pay over the odds but if you didn't it could be an interesting lens for 4 x 5 or 5 x 7.............................................

good luck and regards

Andrew

[Dan Fromm]

The lens' s/n is, according to P-H Pont's chronology, from 1913. 371939 is probably the shutter's s/n, looks like a Compound and FD (for Friedrich Deckel) is consistent with this. Per Pont, the shutter's s/n is from 1914 - 1920. The lens could have been remounted from barrel to shutter.

f/4.5 suggests strongly that the lens is a Tessar IC. Without knowing the focal length one can only guess about coverage. Assume 50 degrees for an early Tessar Ic, later ones have more.

[David Lindquist]

Serial number 227780 falls in one of the gaps in Hartmut Thiele's Fabrikationsbuch Photooptik I Carl Zeiss Jena. Is serial number 371939 the number on the circumference of the shutter? I can't quite make it out. The "F" and"D" make up the logo of "Friedrich Deckel", the company that made the Compound and Compur shutters. They also built high-end milling machines and other machine tools. They continue to build CNC milling machines today as part of DMG Mori. At some point after WWII the shutter manufacturing was spun off.

And as I expected, as I laboriously typed, Dan provided additional useful information. For more history than you probably want on Friedrich Deckel, especially as a machine tool builder, see: http://www.lathes.co.uk/deckel/index.html

David

[photos.on.film]

Wow, thank you so much for this information, Dan and David. You guys are incredibly knowledgeable.

@Dan: I guess I'll have to find out the focal length of the lens and determine whether it's a Tessar.

@David: The serial number 371939 is written on the shutter selection dial below the FD logo.

@Andrew: Haha, it is the same lens indeed. I was the only one to bid on it so got it for £30.

I'm really amazed by the quality as this is probably the oldest piece of photographic equipment I own and it still works brilliantly.

Thank you all once again for your help!

[Dan Fromm]

Hmm. Tessars have two singlets in front of the diaphragm and a cemented doublet behind. Air-glass interfaces make strong reflections, glass-cement-glass interfaces make weak ones.

With this in mind, shine one (1, > 1 will give a confusing mess) at the front of the lens with the shutter closed. If it is a Tessar, you will see 4 strong reflections. Then shine the light at the rear of the lens. If it is a Tessar, you'll see 2 strong reflections and 1 weak reflection. The weak reflection can be hard to see.

[ic-racer]

Is the auction over? Did you win it? I'm curious if it covers large format and the focal length. Have you had a chance to use it yet?

[photos.on.film]

@Dan: I can see at least four very clear reflections in the front and a number of less clear ones. At the back, I can see two very clear reflections and maybe 2-3 minor ones. So I guess this is a Tessar :) Thank you for this extremely helpful test!

Do you also know a way for me to measure the focal length? I've heard that you can focus on something at infinity and then measure the distance between the back element and the image formed?

@ic-racer: Yes I did win it, only because no one else wanted it. I still haven't used it yet as I wanted to figure out what I'm dealing with first.

[Dan Fromm]

Do you also know a way for me to measure the focal length? I've heard that you can focus on something at infinity and then measure the distance between the back element and the image formed?

Its better to measure from the diaphragm. Practically speaking, from the rear of the shutter will do.

[cowanw]

Focal length is the Fstop times the measured diameter of the aperture (from the front) at that Fstop. I think so anyway. Assuming the shutter is labelled correctly.

[arri]

Re: Mystery Carl Zeiss Lens - Anyone know what this is?

I´am sorry to say that this lens is a fake, badly engraved by an hobbyist. You can realise it when you see the doubled numbers of the engravings, Zeiss never did it like this, believe me.
The Zeiss engravings are milled and this is a srcatch marking, this are not milled, it were carved with a diamond or ruby.
The front element is a rear element in real, the design of it is typical for it, the most front rims are chamfered and not plain.
I guess it is a combination of two elements from different lenses.
Maybe the fake it is very old, made in the late 1920th or 30th.
Zeiss lenses were very expensive and had a high reputation and this arouses desires, for the faker to make money and for the buyer to get an unknown rare Zeiss lens.
A lot of fake lenses are in the market, the easiest way is to declare it like a prototype because it makes it impossible to proof that it is a fake even when the buyer has not the knowledge.
When the work is not accurate, like here, it is simple to realise that it can´t be a Zeiss lens.

The optical quality is designed by coincidence, so don´t await any special.

I hope that you did´nt pay so much for it.
I guess the seller has to proof the authenticity and is responsible for what he sells and when it were an official action and he declared it as a Zeiss lens he did´nt makes a good job and you have the right to give it back.

BTW:
The engraving on the shutter: D.R.G.M. means: "Deutsches Reich Gebrauchs Muster" and said that the shutter design and handling is saved by law.

Take care and stay healthy

[Ron (Netherlands)]

Indeed non-original engraving and by the look of it not a front element. I have Zeiss lenses with much lower numbers but all with milled engravings.

[photos.on.film]

I did not pay much for it at all. In fact, I was the only bidder. I guess it makes sense now haha! Now I want to find out what this lens actually is. It does work fine so I think I will just hold on to it. Thank you for your input gentlemen.