A discovery: Dagor-type G-Claron's as the ultimate Casket Set

[carverlux]

Like many on this and other forums, I have used and long since admired the unique quality of Dagors. From century-old Serie III Doppel-Anastigmats to the last Kern MC Gold-Dots, they provide a balance between coverage and sharpness that is hard to beat from 5x7 through 20x24.

For a little while now, I have been reading that the very early G-Claron's were made in a Dagor layout, and were coated. I came to thinking that having a maximum aperture of f/9.0 will have allowed the lens designers to take out the last traces of residual spherical aberration inherent in the Dagor design, which means one of the biggest nuisances of using Dagors - countering focus shift upon stopping down - is finally out of the way of shooting at f/64 and beyond to fulfull the promise of its 85°+ coverage.

So I went searching. And as luck would have it, I have been able to amass all 6 focal lengths of the lost series, and yes, Mr. Galli, there really is a 355 G-Claron made like a Dagor and it is coated! Its filter size is 77mm in the front and 72mm in the rear.

First things first - every one of these are usably sharp wide open, and when stopped to f/22, goes about 9/10's of the way between the Goerz Am. Opt. Dagor (post SN 78xxxx) and the Artar-like Kern Gold-Dot. In rendering 3-D objects, they are very close to the Golden Dagor except they do not have the slight dreaminess from the residual spherical aberration that Golden Dagors have wide open.

Given that their cells are completely symmetical, for as long as cell spacing is observed, they can theoretically be combined in the exact same way that the Zeiss Protarlinsen can. The fact that they were not sold this way probably had something to do with the fact that their intended market were initially photocopiers.

Here are the possible combinations based on their actual focal lengths as stated in the datasheet, the red being a close duplicate of an existing prime combination, which are bolded:

355 355 355
355 305 334
355 267 317
355 237 304
355 208 292
355 153 268

305 305 305
305 267 289
305 237 276
305 208 263
305 153 240

267 267 267
267 238 255
267 208 242
267 153 218

238 238 238
238 208 225
238 153 202

208 208 208
208 153 184

153 153 153

17 focal lengths in total, excluding the 4 very close duplicates. The delta between some of these focal lengths being so small, it may not be a practical 17 but nonetheless, the possibilities exist.

The following are the shutter fitting and hence the required basic spacings. This means that some will need custom adapters to combine, while the 210 to 270 all fit to a Compur/Copal 1. Necessary adapters can be made so all of the cells will fit and/or combine into either a Compur/Copal 3 or a Compur/Copal 1.

355 Compound III
305 Compur 2
270 Compur/Copal 1
240 Compur/Copal 1
210 Compur/Copal 1
150 Compur/Copal 0

Who would have thought that there could be a Dagor Casket Set that covers 85°+ stopped down and has little to no focus shift? To me, they are true gems and you will have to pry hard from my cold, dead fingers.

Carver

PS Attached is a picture of the handsome trio of 270, 305 and 355.

[carverlux]

Here's the rest of the gang: the 150 in a Compur 0 and the 240/210 combo in a Compur 1.

Enjoy!
Carver

[Dan Fromm]

Um, Carver, Goerz wasn't the only manufacturer of Dagor type lenses. At least one of the others sold sets of unmatched cells. See http://www.galerie-photo.com/boyer-lens-optic.html, read the section on the Beryl.

[carverlux]

Dan,

Thanks for the heads-up on Boyer. I am happy to know that there are even more options available for anyone who is looking for Dagor-type lenses.

All the best,
Carver

[cyberjunkie]

I own an old 355mm G-Claron in barrel, that looks exactly the same as the example shown on the first picture of the thread.
There is a pdf on Schneider web site about first generation (?) G-Clarons. The year of the catalog is 1976, and very oddly the 355mm has no infos reported, just "in Vorbereitung", that means "in preparation". But my lens has a serial # of 11 932 8xx, meaning that probably it was manufactured on the first part of 1972.
So these lenses were produced well before 1976!
The optical scheme of 1976's Clarons is clearly a dagor-type: 6 elements in two groups.
It should be quite obvious, but when i read the first post of this thread, i'm not so sure anymore: my lens has a very different filter thread diameter, from what i recall it should be 67/68mm, both in front and rear, while carverlux reports a diameter of 77mm and 72mm.
Just another information: if i remember, in my lens there are four strong reflections per side (and maybe a very faint one, but i could be wrong about it).
I don't have the lens here (i sent it to a friend, he has to make a new retaining flange, while i patiently wait for a suitable Compound III shutter... but i'm not even sure about that!).
If an owner of a Dagor-like G-Claron is reading, please post the serial of your lens.
Better if it's the serial # of a 355mm like mine

have fun

CJ

[carverlux]

Hello Paul,

The quick answer to your question is that my 355 has a serial number of 10 737 xxx. It has a 77mm front filter thread and a 72mm rear filter thread.

The factory shutter for it is a "3" but a Compound III/7, not a Copal 3 or Compur 3. A Compound III/7 has cell threads of M55.69 x 40tpi for both front and rear and a spacing of 37mm. Cells that are made for Compound III/7 threads can be made to Copal/Compur 3 and Adam at SKGrimes would be delighted to show you his magic!

I hope this is helpful to you.

Carver

[Jim Galli]

Copal made shutters for Schneider in 1970 that were a direct replacement including cell spacing and thread for the Compound III/7

I have one just now with a Tele Xenar in it but would sell for probably less than Adam charges for the machine work to convert a normal modern Copal 3

I've been using a 225mm G-Claron for years. Never concerned myself to make up others though.

[carverlux]

Adam is always superb but a Compound III/7-compatible Copal would be much more cost-effective for sure.

I did just recently verify the "casketability" of these lenses by combining a 355 front and 210 rear to make a 300. It performed superbly, in fact no different than a native 305 G-Claron or a 12 inch Golden Dagor at the same aperture.

[cyberjunkie]

Adam is always superb but a Compound III/7-compatible Copal would be much more cost-effective for sure.

I did just recently verify the "casketability" of these lenses by combining a 355 front and 210 rear to make a 300. It performed superbly, in fact no different than a native 305 G-Claron or a 12 inch Golden Dagor at the same aperture.

I just found a defective 210mm Xenar on Compound III, the lens is a little foggy and the shutter seems to fire with the same timigs no matter which are the settings.
Probably a friend of mine will fix the shutter, and the lens cells will be cleaned as best as possible... in the end, much cheaper than having the two tubes precision-machined from a solid aluminium bar. For the moment, i would be more than happy to have the 355mm G-Claron set in shutter, at last!

Just a little obeservation about the dimensions of you lens vs. mine.
The pdf about 1976 G-Clarons available on Schneider web site clearly shows a Dagor-like optical project, and the lenses are clearly asymmetrical in shape, like yours. For the 355mm, as i wrote before, there are no quotes.
The strange is that your lens, made a couple of yers before mine, has a different front and rear diameter as well. My lens has a 67mm thread on both sides.
That makes me think that before the model portrayed on the 1976 catalog, probably there was a different one, at least for the longer focal.
Whichever the external shape, it seems that all the G-Clarons made in the seventies have a Dagor-like optical project.
Unfortunately both the 305mm and the 355mm have non-standard cell threads, so their use as "modern casket" is not so easy: custom made adapters are a must.

All in all, my best compliments for your contribution. Learning never ends, and you made me aware of a very interesting, and potentially useful, new bit of information.

have fun

CJ

[carverlux]

Back in the 60's and 70's many lenses made for one shutter size were sometimes requested in shutters of a different size than in the catalog. So the factory made them but did not always put them in the regular catalogs. For example. I have a 135 Convertible Symmar which according to the catalogs were officially only sold in Compur 0 threads. But mine came in a Compur 1 shutter. The adapters were made by Schneider and epoxied in place. I also have a 150 Componon with a Compur 1 thread that came on a Compur 3 shutter, with factory adapters of course.

Looking at these factory adapters, the level of precision is no more or less than what you'd find in a modern filter step-up ring. So while the cost to do these adapters one off is prohibitive, in volume (and/or from China!) the costs would probably be not so bad.

My curiosity around these G-Clarons' "casketability" is due to the fine level of perspective and bokeh control a multitude of closely-spaced focal lengths gives me. It is more a luxury than a necessity. So venture on and as you come across them, just pick them up as they are not expensive. Over a couple of years, you'd be amazed at what you will have at your fingertips.

Enjoy!
Carver