Xenar 180 / 4.5 Aperture position

[Ivelin Metodiev]

Hello,

I've got a Xenar 180/4.5 (marked Schneider-Göttingen Xenar 1:4,5 F=18cm) in a barrel with no aperture. It was pretty dirty, but I was able to disasemble and clean both groups nicely. I can work around the lack of shutter, but I'd like to modify the barrel to accept waterhouse stops. I'll have a machinist cut the slot, but I am stuck determining the proper position. Can anyone point to a lens schematic or another source to give me the spacing between the aperture and front/back groups?

Thanks in advance!

[Dan Fromm]

There are some f/4.5 Xenar presciptions here http://www.dioptrique.info/base/n/n_xenar.HTM, all scaled for 100 mm. Multiply all dimensions including radii by 1.8 to rescale for 180 mm.

[Ivelin Metodiev]

Thanks Dan, this seems like a good starting point for some experiments. How do you read " distance diaphragme" in these specs - is that the spacing between the diaphragm and the previous element (front to back)? And would that be measured from the center of the element or from it's most protruding edge?

[Dan Fromm]

"distance diaphragme" is the distance between the element in front of the diaphragm and the diaphragm. I'm not sure where it is measured from, ask Eric.

The contact link on his site doesn't work, his e-mail address is eb@dioptrique.info. His English is very good.

[Ivelin Metodiev]

Thanks a lot, I will email him