90mm for 6x17

[SMBooth]

Looking around for a 90mm to fit to a 6x17. I have narrow down the choice to either the Rodenstock Grandagon 90mm f6.8 (or Caltar -N) or the Fujinon 90mmf8. The Nikon f8 is a little out of the budget. Both will cover quite OK but Ive read the Grandagon is designed for less light fall off at the edges. Is this true, and is it worth the extra dollars to pick up the Grandagon over the Fujinon.
If any one has either for sale quite welcome to PM me.

Thanks Shane

[Bob Salomon]

For 617 you should use the faster lenses with their greater coverage. But they still may need the center filter if you want more even coverage.

[Phil Hudson]

I wonder if there is a real difference between comparable (say 100/102 degree) Rodenstock and Schneider wide angle designs and the way that they deal with light fall-off, or whether Rodenstock market the effectiveness of a common design feature more effectively:

"With the Grandagon-N, all the problems which occur in connection with large image angles have been ideally taken care of: The distortion has been reduced to a small residual value; the light fall-off towards the edges has been greatly reduced thanks to an optical trick (“pupil distortion” = the entrance pupil diameter increases when viewing at an angle); the sharpness sets standards for this class of lenses.

I wonder if this "optical trick" is also inherent in the Super-Angulon design?

[engl]

I wonder if there is a real difference between comparable (say 100/102 degree) Rodenstock and Schneider wide angle designs and the way that they deal with light fall-off, or whether Rodenstock market the effectiveness of a common design feature more effectively:

"With the Grandagon-N, all the problems which occur in connection with large image angles have been ideally taken care of: The distortion has been reduced to a small residual value; the light fall-off towards the edges has been greatly reduced thanks to an optical trick (“pupil distortion” = the entrance pupil diameter increases when viewing at an angle); the sharpness sets standards for this class of lenses.

I wonder if this "optical trick" is also inherent in the Super-Angulon design?

The "optical trick" is a tilting exit pupil, several of the wide-angle designs have this. The Super Angulon, Grandagon, Nikon SW, Fuji SW/SWD, perhaps some more. These lenses have close to cos^3 theta falloff (where theta is angle from optical axis).

Most lenses do not have this property and instead have cos^4 theta falloff. This includes some wide angles lenses, like the Super-Symmar XL.

[Phil Hudson]

Most lenses do not have this property and instead have cos^4 theta falloff. This includes some wide angles lenses, Schneider XL is one of them. The Schneider XL lenses are commonly used with a center filter to even out falloff.

Is this true for Schneider Super-Angulon XL or Super-Symmar XL, or both?

[SMBooth]

Thanks so far, Engl, you seem to be saying that any (Super Angulon, Grandagon, Nikon SW, Fuji SW/SWD) would do the trick.

[engl]

Sorry, my first message was a bit inaccurate and I edited it. The Super-Angulon XL seems to be cos^3 (tilting pupil) and the Super-Symmar XL is cos^4 (not tilting, more falloff).

[Steve Goldstein]

You need to be careful about flange focal length unless your 6x17 has a bellows. There's several mm of variation between the various brands; you can run into trouble with a camera having fixed cone.

[Phil Hudson]

Sorry, my first message was a bit inaccurate and I edited it. The Super-Angulon XL seems to be cos^3 (tilting pupil) and the Super-Symmar XL is cos^4 (not tilting, more falloff).

I think I get it now - many thanks for your input!

[Gem Singer]

Take a look at the previously owned f6.8 90 CaltarII-N MC lenses that are listed here---

www.keh.com