Rodenstock Wide Angle Eikonar 130mm f/12

[arri]

Today I finished the special mount for the Rodenstock super wide angle lens. I have to make a sunk mount for the lens to aware that the rear lens shutter of the Sinar system limitate the angle of view.
Rodenstock listed the lens with 105°.
So I have to test it with 18x24cm sheet film size. Here the lens has to cover 100° angle of view.
In the corners the sharpness ist not perfect but I find it realy remarkable that the corners are not dark, the lens shows only minimal vignetting.
The lens has a very good sharpness and has no focus shift like so many of the Dagor style lenses have.

I take the sample with f/45.
Fujifiilm UM-MA xray film, Moersch Eco developer, rotation, Sinar Norma 8x10"

[xkaes]

Do you know the optical design of the lens? As far as I know, Dagors are 6/4, but don't have 100° coverage -- let alone 105°.

[arri]

The lens has two fully cemented groups of three lenses each, like the Dagor.
Goerz made a wide angle Dagor with 100° as well and the Eikonar is a similar design.

[J. Patric Dahlen]

What Willy Frerk had to say about the Eikonar in 1927.



This book cover shows the Eikonar design. It's similar to the Dagor, but the shapes of the elements are different. https://www.lindemanns.de/shop/migal...ima/64021r.jpg

[Jason Greenberg Motamedi]

Thank you for posting! I have a 130mm f12 Rodenstock Weitwinkel Perigon, which to my knowledge is the same design as your Eikonar but coated and in shutter. In my experience it just illuminates 8x10 (so ~100°) but with similar soft corners as your image. Regardless it is a wonderful small lens in a unique focal length. I love mine for 5x7.

[arri]

Thank you for posting! I have a 130mm f12 Rodenstock Weitwinkel Perigon, which to my knowledge is the same design as your Eikonar but coated and in shutter. In my experience it just illuminates 8x10 (so ~100°) but with similar soft corners as your image. Regardless it is a wonderful small lens in a unique focal length. I love mine for 5x7.

I know the Perigon, I heard that 38 of the 130mm lenses were coated in the late 1940th.
The Perigon is a copy of the Zeiss Jena Protar, four lenses in two groups but not symmetrical. With this design a better anastigmatism correction were possible.
The lens is mentioned in the Linhof catalog of 1935 and superseded the WW Eikonar.
In this years Rodenstock had no fully cemented Dagor style lens in production.
The four element dialyt system, the Eurynar were their bestseller. Also the Ysar, the Rodenstock Tessar clone.