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Janko Belaj
14-Jun-2005, 06:38
As you probably know, I'm searching for some small w-a lens (Goertz Wide Angle Dagor or Kodak Wide Field Ektar) and today there are two dagors listed on ebay. One is 90mm and is stated that will cover 5x7"(?) it is f1:6.8 (item=7523399174), and the other 105(?)mm (item=3869122525).
When I look in articles on this site, or on lf lens specs on graflex.org, such lenses does not exist. Whom should I trust?

Tnx. (again ;-))

Michael Jones
14-Jun-2005, 06:44
Go to these sites and review the literature. This should answer your questions.

http://yandr.50megs.com/gz/artar1/artar1.htm

http://yandr.50megs.com/gz/pr/pr.htm

Good Luck.

Mike

Tracy Storer
14-Jun-2005, 07:57
There were 90mm and 105mm Dagors, though I doubt either one will cover 5x7. I have a coverage table (from a B+L catalogue?) stating the 105 will cover 4x5 at f/45.
This seems consistent with my real-world observations of coverage of bigger Dagors. (somewhat less than 90 degrees)

Tracy Storer
14-Jun-2005, 08:02
Just looked at the ebay auction, the 90mm is f/8 not 6.8. (6.8 is a Series III, "regular" Dagor)
It is a WA Dagor, and probably WILL cover 5x7.

Ole Tjugen
14-Jun-2005, 08:06
The Goerz Wide-Angle Dagor 3 5/8" is stated to cover 5x7", and it might be true at small apertures. The same is true of pre-WWII Schneider Angulon 90mm/f:6.8, by the way, with less chance of vignetting. But only the prewar model...

Paul_5410
14-Jun-2005, 08:07
Janko,
The links above will take you to some excellent scanned company data brochures. However, I have also found in my hunt for info for my RD Artar that the Goerz Co tended to be VERY conservative in its lens ratings (and it seems to me) only stated the optimum image area of coverage and NOT the circle of coverage. This is only a theory but I am trying to resolve the mystery. . .
Paul

sanking
14-Jun-2005, 16:56
In my opinion the 90mm wide angle Dagor, which is fairly similar to a 90mm Angulon f/6.8, gives unacceptable performance on 5X7. Yes, the circle of illumination is large enough to cover the format, but even on stopping down to f/45 or more performance on the corners is unacceptable.

If you expect to get decent performance on the corners from a 90mm lens on 5X7 you need a more modern lens. A past generation 90mm f/8 Super Angulon or 90mm Ilex Wide Field Caltar, not very expensive, will give much better results on 5X7 than a 90mm Dagor or Angulon.