Mystery Lens

[Nick Venechuk]

I have a lens which has few markings. No manufacture name or any of the usual information. The only marks are hand written numbers inside the barrell of each lens element, and a serial number on the rear lens assembly.
The shutter has settings from F 8 to F 64, and by comparing the infinity focusing distance with known lens (150mm, 120mm, and a 90mm) I've determined that this lens is a 165mm, or 6 1/2".
The lens construction (thanks to some great information on this site!) seems to be a Dagor, with three elements each at front and rear, and there is a double reflection within each lens, one bright and one dim.
The serial number style is the same as a Goerz, and if so, would have been made by the American company with a manfacture date of about 1935 to 1938.
But a lot of all this is simply guess work. All I'm sure of is the focal length.
So, does anyone have any knowledge of something like this? Why are there no markings on the lens rim? Could this have been made for the military? Or could this be a low-grade lens made for some type of fold-out camera?
Inquiring minds, and all that.
Nick

[Steven Tribe]

My guess is that it is a rapid rectilinear lens (f8) originally sold in a a barrel which had all the data. Goerz tradition was a number on both the front and rear cells. The number on the compur will give some idea, perhaps, of when the conversion was made. I'll do a quick check tomorrow to see if I can find an RR type with stamped rear numbers and the distinctive edges - not many reached that high serial numbers in the RR era. If I had to guess - it would Busch who sold very well and had barrel data engraving.

[Nick Venechuk]

Thanks Steven, I'd begun to think that this lens was such an orphan no one could recall anything about it. The serial number on the shutter is 686503.
So it might be a rapid rectilinear? I'll have to read up on that design.

Anyway, thanks again!
Nick

[Steven Tribe]

Well the shutter is from 1925.

[Nick Venechuk]

Steven,

Thanks for the information about the Compur shutter. For what it's worth, it still seems to be accurate, even at the slow speeds.

There is a Goerz lens with XexcelL Sector shutter listed on Ebay. The lens does not appear to have any markings on it, the only info is on the face of the shutter, and it looks somewhat similar to the one that I have. Do you know of a resource for information about this shutter?

If I can get my 'honeydo' projects finished this weekend I'll post a few test photos using the 6 1/2" lens. BTW, there are a great number of small specks within both layers of the front and rear lens. I've seen fungus in a lens before, and this is nothing like that. I'm thinking that these specks are bits of the balsam glue which have migrated between the lens elements. They are somewhat uniform in size and not linked together. Or could it be something else?

Nick

[Steven Tribe]

The xexcell wasn't made in great numbers - the problem for you is that think it was made at the period when Goerz was selling the syntar, celor as well as the dagor! I thought it might have been from the pocket tenax series which were made for over a decade with a similar integral shutter. But all their mounted front cells seem to have had an engraving. I think you are right about it's origins.

[Lynn Jones]

Dagor, Celor, Dogmar were all similar 6 element (inversly ordered by time frame). Zeiss bought the Goerz company around 1925 or so, sold it to B&J arond 1927.

I've never seen one as unmarked as this. If it is a Dagor it should cover around 65 degrees and be pretty good.

Lynn