Differences in Dagors over the years?

[Greg]

As far as I can tell there have been several incarnations of Goerz Dagor formula lenses produced over the years:
Goerz Double Anastigmat
Dagor (the classic?)
Goerz Gold Dot Dagor
Schneider Gold Dot Dagor
? Blue Dot Trigor?
Swiss Kern Goerz Dagor
Anyone out there know of the differences between them?

Just read in an article on LF lenses from Eastern Bloc Countries (1945-1991)
Doppel-Anastigmat f/6.8 180mm, 210mm, and 240mm Dagors
Orthoanastigmat f/8 190mm inverse Dagor
Orthoprotar f/18 250mm inverse Dagor

[Drew Wiley]

According to Kingslake, the cemented double triplet formula known as Dagor goes clear back to 1892. So that means quite a bit of micro-evolution involving different glass types, shutters, and coatings. The last of them (other than a limited production Schneider XXL) was the Swiss Kern 14 inch multicoated Dagor made for Schneider. I don't know when production stopped, but probably in the 1980's. This had higher contrast and better color rendition than any other lens I've ever used, in any format. But I was mainly shooting large format color transparencies at the time, and found the contrast to be just too much. So I replaced it with the previous Kern single-coated Dagor, which still had plenty of contrast due to the only four air/glass interfaces inherent to the Dagor design. There was also an eight inch single-coated Kern Dagor. Prior to that, Goerz and American Optical made em, and so you go, further and further back. The 14 inch Goerz Blue Dot Trigor was a wide-angle process lens that somewhere down the line a few people found to work quite well as a taking lens. Lots of them were probably thrown away when process camera usage became largely obsolete, so now the few that remain command high prices. I've never tried one. As far as shutters go, I absolutely hated the Compur 3 shutter the multicoated Kern came with. It had no T setting and a terrible buzz vibration. I've had more than one of these lenses, so it wasn't a fluke. The single-coated Kern came in a Copal 3S - a shutter I love. But neither of these lenses are good on film larger than 8x10 if movements are needed, because no.3 shutters have a bit of mechanical vignetting. The older f/7.7 dagors covered more simply because of the big 4 or 5 shutters, I suspect. It doesn't mean the corners of the field on ULF are as good; but that's seldom an issue with contact prints. I have no experience with early or wide-angle dagors, so someone else will have to explain those.

[John Layton]

Owned a 14 inch Swiss Kern Blue-dot Trigor years ago, and remember testing this by taping strips of 35mm Agfapan 25 to the inside of an 11x14 holder (center and edges), and resulting negatives were pretty much equal to those taken with this same film with my Leica with version 3 (German) Summicron set at f/8...more than impressive!

[Mark Sawyer]

I own 2 modern (1950s?) coated gold-rim Dagors, 8 1/4-inch and 12-inch. The 8 1/4-inch just covers 8x10 and is sharp to the corners. The 12inch just covers 11x14 and is sharp to the corners. I have 2 12-inch and 1 8 1/4-inch older Dagors (1900s-1930s?), and while they are quite sharp in the center, all get soft at the corners in the above mentioned formats.

[karl french]

So many threads on Dagors. Lots of interesting ready to do in archives.

[Drew Wiley]

None of my Kern Dagors were as sharp or apo corrected as my Fuji A's, G-Clarons, or even Nikkor M lenses, and certainly not in the league of my Apo Nikkor process lenses. But I'm referring to nitpicky overkill in that respect. Their tangential performance at strong tilts and close-up performance is also less. So I think their overpriced cult status is a bit exaggerated. But they do have a particular rendering of microtonality that is quite rewarding; and these later Dagors are in fact sharper than older plasmats. They were hard to make, since each half had to be truly symmetrical. Front and back elements should have matching numbers somewhere and not be cobbled together randomly.

[Leigh]

I have an 8-1/4" Goerz Gold Dot Dagor made by Kern in Switzerland.

The front and rear cells have matching serial numbers.

I've not tested it for coverage.

- Leigh

[Tin Can]

Include old LFPF threads on Dagor 'type'.

I have a Schneider Kreuznach Doppel-Anastigmat Symmar f=6,8 F=30 cm (mounted in Compound-shutter) as discussed below.

https://www.largeformatphotography.i...ll=1#post98509

[Dan Fromm]

Randy, thanks for bringing up other 6/2 double anastigmats. Boyer made dagor clones -- some of their prescriptions are extremely like Goerz patents -- called Beryl, Beryl-S and Emeraude. All to the same prescriptions. Berthiot made a variety of such lenses, trade names Eurygraphe and Perigraphe. Early G-Clarons are Dagor types. And then there are real Dagors made under license by some UK manufacturers. I'm sure I've missed many others.

[Drew Wiley]

There were also reverse dagors, with a slightly different triplet configuration. Once again, Kingslake is good for the early history of all this.