On Sat, 14 Sep 2002, Christiane Roh wrote:
> Welcome to the list ! I've Schneider lenses so I don't know the right
> answer to your question, but LF lenses are discriminated by their coverage
> (the width of the image they are able to project on the groundglass), which
> can vary for the same focal length. I suspect that N could be for Normal, W
> for Wide and S for Superwide coverage.
I looked into this idea, and here is what I found:
(All Rodenstock)
Lens Angle of coverage Image Circle (@f/22)
_________________________ __________________ __________________
Grandagon N 200mm f/5.6 102 deg 495mm
APO Sironar N 210mm f/5.6 72 301
APO Sironar S 210mm f/5.6 75 316
APO Sironar W 210mm f/5.6 80 352
______________________________________________________________________
Rodenstock refers to the Grandagon N series as having "super wide
angle of, coverage".
They describe the APO Sironars as "an all around lens" (?).
APO Sironar S: " Like the APO Sironar N, its applications are
practically limitless. The angle of view has been increased to
75 deg to permit more shift, which permits applications that require
large parallel shifts to correct the perspective optical design."
The Sironar W: "..can also be used as a wide angle."
And from all that, it seems like the "W", "S" and "N" do not
define angle of coverage or image circle. The two Ns have very
different coverages and image circles. One of the Ns (Grandagon)
has the largest angle of coverage and image circle, and the W falls
somewhere in between.
--- Luis
