[LargeFormat] Carl Zeiss Dagor 180mm f9

[Richard Knoppow]

----- Original Message ----- 
From: "Timothy Atherton" <tim at KairosPhoto.com>
To: "f32 Large Format Photography Mail List" 
<largeformat at f32.net>
Sent: Friday, September 30, 2005 6:08 PM
Subject: [LargeFormat] Carl Zeiss Dagor 180mm f9


> Does anyone have any information on this lens at all?
>
> thanks
>
> tim a

   The f/9 Wide Angle Dagor is a design by Franz Urban 
covered in USP 1,641,402 The lens was made by C.P.Goerz and 
by Zeiss after taking over Goerz. In the USA Goerz-American 
made an f/8 version of the wide angle Dagor but I don't have 
a patent number or prescription for it. The f/9 Dagor has a 
claimed coverage of 100 degrees. This is not much more than 
the 87 degrees claimed for the f/6.8 standard Dagor but the 
corrections at the outer parts of the image are probably 
better. The lens has a very good reputation. Other than its 
speed and maximum coverage its characteristics will be about 
the same as a regular Dagor although for similar focal 
lengths it probably has less zonal spherical aberration 
because of the slower speed.
   The German versions of this lens seem much rarer than the 
f/8 American version. I have no idea of its value other than 
condition is everything in a lens. While modern wide angle 
lenses have the advantage of more advanced design types 
allowing higher speed for a given angle and wider maximum 
angles they tend to be large and heavy. Older types like the 
W.A.Dagor and W.A.Protar offer the advantage of very good 
performance in a much smaller and lighter package.

---
Richard Knoppow
Los Angeles, CA, USA
dickburk at ix.netcom.com