150mm f/5.6 Rodenstock Sironar spacing info?

**pacviewcam** · 3-Jul-2021, 21:57

I recently bought a large box of lens elements, probably removed from their shutters so the shutters could be used for something else. (A sure sign of a serious case of GAS)

Among the chaos, I've found that I have 3 sets of the 150mm Sironars. I believe this is the first of that line of lenses -- it's definitely not the Sironar S or later, or Apo Sironar. Another proof of this is that the rear element is much smaller than the front element.

Interestingly, two of the three sets exhibit substantial separation in both front and rear elements. One set has no perceivable separation. I've read that the first line of Sironars often exhibit this separation due to a change in adhesive at Rodenstock during that period. All three sets are pretty clean and scratch free.

I mounted the clear set in a Copal #0 shutter, and immediately found that when I screwed in the front element, it stops the shutter speed dial from turning. This indicates to me that the front element (at least) needs a spacer.

I haven't been able to find any data whatsoever about how to set this up. I think it safe to assume that both cells may need spacers.

Anyone who's reading this, if you have a functional sample of this lens, could you send me at least a measurement of the total length, front to back, of the lens "unit" mounted in its shutter? That, at least, would give me something to go by in figuring out how to shim this beast.

Also, from there I could probably extrapolate how to shim both cells, assuming that the glass of each element should be at equal distance from the aperture.

Any other info (diagrams or specification table) would be most welcome. I'd really like to try this thing out on film one day (not important, but fun, and who knows...?).

Thanks in advance for any help on this.

**Dan Fromm** · 4-Jul-2021, 07:25

https://www.pacificrimcamera.com/rl/00863/00863.pdf

This site has resources, some slightly hidden. The first post in this https://www.largeformatphotography.i...mainly)-lenses discussion has a link to an annotated list of links to sites etc. of interest to LF photographers, including the link above. Use the list before asking questions.

**RandyB** · 4-Jul-2021, 09:23

My 150mm Sironar is of that era (1975) and it did develop separation, it was still in warranty so I sent it back to the importer, Berkey Marketing who sent it back to Rodenstock. They fixed the problem and it has been trouble free since. My lens has the Copal shutter and does not have any spacers/shims. Perhaps there is something up with the face plate of your shutter. The front component group should tighten against the mounting block and not actually touch the face plate.

**pacviewcam** · 5-Jul-2021, 07:02

Thanks very much for the replies.

Dan, after I posted I continued my search for data, and I did blunder upon the links you provided. I'm glad they're documented on this thread, so thanks very much.

Randy, I appreciate the info about how your lens doesn't have any spacers or shims.

One other line of search that I took up was looking for as many images of that model of lens that I could find, and I came to realize that the Copal #0 that I've used to test the lens is too new. The model of shutter that was originally on the lens doesn't have the raised "ridge" around the outer circumference just inside the speed setting ring. "Ridge" really isn't the right word, more like a partial semicircular bulge, but I think you know what I mean; the older lenses have a flat plane at the front. So the outer circumference of the lens element housing doesn't press down on anything at the front of the older shutter.

Nonetheless, on the newer shutter the overall length is 55.7 mm (which prevents turning the speed setting ring); the mechanical specs in the literature from 1982 calls for 55.5mm, so the difference is only .2mm. I put it on a camera and raised the front standard as far as possible with a bag bellows, and the sharp image circle (trees at infinity focus) was pretty impressive.

Yesterday I found a "beater" lens in an older Copal #0 on eBay, so one day soon I'll be able to check the thing out in its original shutter model. We'll see how it goes.

Meanwhile, thanks so much to both of you for your replies and the great info.