Quote Originally Posted by ausphoto View Post
No, no diaphragm and the mechanism doesn't allow for one either it seems.
The lens mount (which is cast!) has threads into which the two units screw into....the lens spacing as shown in the diagram is correct as far as right and left units are concerned. Spacing of the two main units to each other is correct within 1/4 inch. I am not sure how the whole assembly was mounted, and whether it was encased, and how. The retaining rings at the ends of the lens are well made and there is nothing missing there.

Given that the serial number was CAST with the lens mount, there must be quite a few of them. The recurrent serial is 1095-18xx, with the individual pieces then labelled with scratched in numbers.
Thanks for the additional detail. Aerial camera lenses were made with fixed apertures. I have a 3"/4.5 Biogon type that has a shutter but no diaphragm. And some were made with cast barrels.

I'm not sure how to tell how many examples of a lens were made. The s/n smells like an Elcan one. These have the form tttt-nnnn, where tttt is the lens' type and nnnn is the individual lens' sequence number. There's no type 1095 in my Elcan C-series reconnaissance lenses catalog, but this proves nothing.

I'd been doubting that its an aerial camera lens because it seems to have come apart easily. The ones I've had (1 Ross, 1 S.F.O.M., 1 LOMO, 3 Elcan, 3 TTH, 20 Zeiss) were all made to be hard to disassemble. This to resist vibration. But again, if yours came apart easily that proves nothing.