View Full Version : Servicing a Rodenstock Sironar 150mm

25-Sep-2009, 14:52
Is there any DIY way to service this lens whose shutter is sticking on exposures under 1/15 sec. If I give it several taps the diaphragm will eventually close but clearly it is impossible to use until the issue is sorted. The lens also seems to have a defect in the front glass which looks like an oil slick spreading around the glass creating a line on the ground glass viewing screen. As yet I haven't taken any pictures with it but was wondering if it can be or is worth servicing professionally.
Thanks for any thoughts

Bob Salomon
25-Sep-2009, 15:21
It sounds like you have an old Sironar that has developed separation. The shutter may be repairable by a technician, if it is the old Compur parts may not be available.

26-Sep-2009, 00:11
It's possibly in a Compur shutter, sometimes they can be resurrected quite easily with a few drops of Iso-Propyl alcohol or acetone. You need to remove front & rear elements then place 3 or 4 drops on the shutter blades and fire the shutter a few times, that is often enough to free up the slow shutter speeds. Then let it dry completely before re-assembling.

As the glass is de-laminating the shutter is worth far more than the lens so be careful :D

I have a similar early Sironar, unfortunately these were amongst the first Rodenstock lenses to use modern lens cements instead of Balsam and many of them suffer this problem, in fact you very rarely see early Sironar's for sale second hand now. Some early Grandagon's and enlarger lenses suffered the same way.

My Sironar is usable still with no image degradation, but it's alarming to see. It's been out on loan to an Italian photographer and used with no problems.


My guess is mine's best left as is, it's a spare lens/shutter and any repair to the lens itself would cost far more than a better second had lens.

I have a few other later Rodenstock lenses (Sironars Grandagons etc) and the issue of de-lamination had been entirely eliminated by the late 70's/early 80's. I'm sure that Bob Salomon has posted on this Forum that he's never come across a similar problem with any of Rodenstok blenses his company have sold.

It's our bad luck to own the early Sironar's LD


26-Sep-2009, 00:34
Many thanks for your advice. It looks like a trip to the bank manager!