A mysterious lens - Help need with identification please

[JulianR]

I bought this lens on ebay from a seller who got all the details wrong (from another listing). The only information he was able to tell me was that the person who sold it to him said it was a military lens. I have a link to a picture and data on it via my Facebook page https://www.facebook.com/Cave-Art-Fi...57791/timeline. At the time it was incorrectly referred to as a Busch lens. It is a big old beast of a lens. It is a brass tube with a glass lens at each end and the lens on the top unscrews. There is nothing else inside the tube. As you can see, it is stamped with the markings W6/JD/9055 10" 2884. There are no other markings. This may or may not be a camera lens, although I can get it to image on my EOS-M digital camera.

I've got nowhere in my own research and I hope that you can shed some light on this. Thanks in advance.

[Steven Tribe]

10" focal length projection lens (cine?). Arrow shows the end that goes into the mount.

The numbers/letters look like a military registration/stock reference. The end with a cell has a pair of lenses and the internally mounted lens is the petzval achromat (probably!).

This type of lens is very common and Busch made a lot of them.

[Mark Sampson]

The marking at the end of the barrel looks like the 'broad arrow' that has designated property of the British government for over 200 years. could it have been made for the Ministry of Defence?

[Steven Tribe]

Yes it does look more like the "crows foot" than the usual arrow with rudimentary feathers.

[JulianR]

10" focal length projection lens (cine?). Arrow shows the end that goes into the mount.

The numbers/letters look like a military registration/stock reference. The end with a cell has a pair of lenses and the internally mounted lens is the petzval achromat (probably!).

This type of lens is very common and Busch made a lot of them.

It might still be a Busch but that information was part of the erroneous information from the seller. I had thought that the serial number was military. A military projection lens? Puts the image into my head of the 1st Queen's projectionists regiment.

[JulianR]

To you and to Steven, it seems to be very much a plain arrow ie ↑ . The only correct information I have is that is SUPPOSED to be a military lens. I have properly measured it and is 85mm tall and 55mm across giving a lens diameter of 50mm. This would make it an f/5 in f stop terms. The BIG QUESTION next is of course, just how old is it?

You can see from my Facebook page that I have been experimenting with attaching old lenses to modern cameras. I have a lens, a Beck with a Lukos shutter, that I know actually served in the trenches during WW1. I intend to use it at the Remembrance Day commemorations on the 11th November for both stills and video.

Anyway thanks a lot to all of you although it still retains quite a lot of its mystery.

[JulianR]

https://www.etsy.com/uk/listing/2200...?ref=related-1

This seems very much like mine incl an arrow (but at the "wrong" end and the "wrong" arrow) and the size is similar 73mm x 52mm

[Steven Tribe]

Yes yours is at the wrong end and this new one has the more usual arrow. I have had and sold a half dozen of these with various makers and fancy names suggesting end use. This one of the standard diameters which fits into a friction mount - the other common diameter is around 46mm

[DKirk]

The "JD" bit may suggest a Dallmayer lens - http://www.thedallmeyerarchive.com/R...ification.html may give some indications to its history.

[JulianR]

Well well well. It pays to read around this forum. I have now discovered that whilst the top part that unscrews is a heavy bit of glass, the base is indeed two thin lenses with an air space between. The both faces of the base are gently curved, which is a shame as it appears that you guys are really into flat bottoms. The front face of the other lens is curved but the inside is flat. The rough and ready measurements has it as an f/5 (and a bit) and I think that this would be more likely an f/6 perhaps. The serial numbers are possibly a misnomer as they are stamped and may be from army use if indeed it is a military lens. The clean glass make me think that it might be more 20th than 19th C.