199/4.5 Dagor-S design type?

[Dan Fromm]

Does anyone know this lens? The best information I've been able to find is that it is not a Dagor type.

No mention in the VM, not a surprise since the VM is weak on US-made lenses.

Thanks to Google, I know that Goerz American Optical Company (no connection to American Optical Company) changed its name to "Goerz Optical Co. Inc." in 1962. See http://www.globalmatter-lab.net/catalog.htm

Thanks to Google applied to this site, probably not a Dagor type. Perhaps 4/4 (see http://www.largeformatphotography.info/forum/showthread.php?28903-Dagor-S-lens).

My question isn't all that new, its been asked before but hasn't got a definitive answer yet.

[Jason Greenberg Motamedi]

I don't to have much to add since my comment in 2007, but I did speak with Geoff and Jeff at Lens & Repro about the lens (they had one in stock at the time), and they were fairly certain it was a lens from some sort of copier. Since then I have only seen one or two be offered for sale.

[Tracy Storer]

Probably another version of a "Dagor type B" which was basically a Dogmar / Gotar under another name.

[David Lindquist]

Does anyone know this lens? The best information I've been able to find is that it is not a Dagor type.

No mention in the VM, not a surprise since the VM is weak on US-made lenses.

Thanks to Google, I know that Goerz American Optical Company (no connection to American Optical Company) changed its name to "Goerz Optical Co. Inc." in 1962. See http://www.globalmatter-lab.net/catalog.htm

Thanks to Google applied to this site, probably not a Dagor type. Perhaps 4/4 (see http://www.largeformatphotography.info/forum/showthread.php?28903-Dagor-S-lens).

My question isn't all that new, its been asked before but hasn't got a definitive answer yet.

I don't claim that the following is definitive, in fact it probably raises at least as many questions as it answers.

First of all I have a copy of Art Kramer's column from the May 1969 issue of Modern Photography. In it he reports on "...a new Dagor S series…" "The new lens is called the Dagor S. It is not the same lens although it has the basic six elements grouped into two cemented sets of three elements each. The old old Dagor was symmetrical, that is the front element was a mirror image of the rear. The new Dagor S is asymmetrical. But most important, The Dagor S is a faster lens with a maximum aperture of f/5.6 instead of f/6.8." And "The new Dagor S will have the same superior coverage as the old lens." He further says that, in general, barrel mounted lenses will be corrected for an image-to-object ratio of 1:5, i.e. for projection and process work, while shutter mounted lenses will be corrected for an image-to-object ratio of 1:15 for general photography.

Then in the January 1972 issue of Popular Photography there is Bob Schwalberg's history of Goerz and the Dagor. "One future certainty is the long-rumored f/5.6 'Super-Dagor' which will be produced in two versions, with a hyphenated 'SL' for close-in reproduction purposes. and 'SV' for a conventional infinity to about 10 focal lengths range. These coming f/5.6 lenses will be a modification of the standard Dagor design in which the positive meniscus third lens in each cell is air-spaced instead of cemented." (Compare this with Kramer's description which sounds to me to be of two fully cemented cells of three elements each for a total of four air-glass surfaces".)

Neither Kramer nor Schwalberg make any mention of these new Dagors being convertible.

I've not seen any evidence that these "new" Dagors ever really went in to production. I don't know how (or if) these f/5.6 Dagors relate to the f/4.5 Dagor-S in question.

Thank you Dan for re-iterating the fact that the C.P. Goerz American Optical Company was never part of AO (American Optical), makers of eye glasses and at one time microscopes and optics for a wide-screen motion picture process. I'm afraid that misconception is never going to be laid entirely to rest.

Finally, looking at the link you provided, it looks like you mis-quoted Michael Buchmeier on the year the company name was changed to Goerz Optical Company Inc. It was 1964 not 1962. I've wondered if they got tired of being confused with AO.
David

[Dan Fromm]

David, thanks for the reply. Also for correcting my date error. When I searched I found discussions of the Kramer and Schwalberg pieces, didn't mention them because the 199 that caught my eye is f/4.5. As far as I know there's never been a dagor type faster than f/6.8. If I'm mistaken about this I'd love to know it.

Re Kramer's column, asymmetrical dagor types are ancient. The ones I know of are all fairly slow, though, so his report of f/5.6ers is a surprise.

Super Dagors as described by Schwalberg sounds like a plasmat. We're used to plasmat type taking lenses from the big four that are no faster than f/5.6 but Boyer's Saphir B enlarging lenses are all plasmat types, some as fast as f/3.5. Boyer's extremely obscure Saphir Color taking lenses are as fast as f/4.5. These are convertible plasmats, fine lenses according to the VM but not quite as good as equivalent convertible Symmars. IIRC towards the end Ilex made some f/4.8 convertible plasmat taking lenses; people here have spoken highly of them. So f/4.5 doesn't rule out a plasmat.

Cheers,

Dan

[Jason Greenberg Motamedi]

...The new Dagor S is asymmetrical...

Hmm, as I think back this is also what I was told by the folks at Lens & Repro, that the Dagor-S is an asymmetrical Dagor, but when we looked at the reflections together we all agreed that it looked like a symmetrical 4/4 design.

[David Lindquist]

David, thanks for the reply. Also for correcting my date error. When I searched I found discussions of the Kramer and Schwalberg pieces, didn't mention them because the 199 that caught my eye is f/4.5. As far as I know there's never been a dagor type faster than f/6.8. If I'm mistaken about this I'd love to know it.

Re Kramer's column, asymmetrical dagor types are ancient. The ones I know of are all fairly slow, though, so his report of f/5.6ers is a surprise.

Super Dagors as described by Schwalberg sounds like a plasmat. We're used to plasmat type taking lenses from the big four that are no faster than f/5.6 but Boyer's Saphir B enlarging lenses are all plasmat types, some as fast as f/3.5. Boyer's extremely obscure Saphir Color taking lenses are as fast as f/4.5. These are convertible plasmats, fine lenses according to the VM but not quite as good as equivalent convertible Symmars. IIRC towards the end Ilex made some f/4.8 convertible plasmat taking lenses; people here have spoken highly of them. So f/4.5 doesn't rule out a plasmat.

Cheers,

Dan

Yes, Ilex sold a 6, a 7 1/2 and an 8 1/2 inch f/4.8 convertible plasmat under the name Acuton. There's an 8 1/2 inch Acuton currently listed here for sale. Also Calumet sold the 8 1/2 inch lens under the name Ilex Caltar-S (think that's right). And the original Plasmat designed by Dr. Paul Rudolph for Meyer was an f/4.5 lens.
David

[John Schneider]

"One future certainty is the long-rumored f/5.6 'Super-Dagor' which will be produced in two versions, with a hyphenated 'SL' for close-in reproduction purposes. and 'SV' for a conventional infinity to about 10 focal lengths range...

I remember someone on eBay a few years back selling both an SL and a SV Dagor. I remember one of them being 50mm f.l., but I don't remember which one.

I do have a 199mm f4.5 Dagor-S, and I can confirm that it is neither a Dagor, plasmat, or Artar/Gotar/Celor design. I have never mounted it nor checked the coverage in any way, so I have no clue what it can do. Both front and rear cells have deep curves, all convex w.r.t the aperture. I checked the reflections, and there are 4 bright reflections/cell, plus 1 fainter reflection. The fainter reflection corresponds to a nearly flat lens surface. I can't find my copy of Henney and Dudley, but my guess would be a double Gauss design something like shown below:

[John Schneider]

fff

[Dan Fromm]

Thanks, John.

[Jim Galli]

Ross Wide Angle Xpres used so successfully as an aerial lens is I believe, an f4 plasmat.

[Arne Croell]

I remember someone on eBay a few years back selling both an SL and a SV Dagor. I remember one of them being 50mm f.l., but I don't remember which one.

I do have a 199mm f4.5 Dagor-S, and I can confirm that it is neither a Dagor, plasmat, or Artar/Gotar/Celor design. I have never mounted it nor checked the coverage in any way, so I have no clue what it can do. Both front and rear cells have deep curves, all convex w.r.t the aperture. I checked the reflections, and there are 4 bright reflections/cell, plus 1 fainter reflection. The fainter reflection corresponds to a nearly flat lens surface. I can't find my copy of Henney and Dudley, but my guess would be a double Gauss design something like shown below:
John,

why not a Plasmat? The reflections you describe would go with either a Planar or a Plasmat, both are 6/4; except for the outermost reflection, it is sometimes hard to tell from what "depth" a reflection comes.

[John Schneider]

why not a Plasmat? The reflections you describe would go with either a Planar or a Plasmat, both are 6/4; except for the outermost reflection, it is sometimes hard to tell from what "depth" a reflection comes.

I guess I had it in my head that it was a double Gauss, but you could be right as well. The mechanical design is such that you can only pull out the lens elements by unscrewing the trim ring around the front element and going in that way, and I have no strong desire to do that to a lens that doesn't need cleaning. But someday my curiosity may get the better of me...