Using a 9/240 G-Claron as enlarging lens

[Drew Wiley]

Dan - I was referring to the last generation of G-Clarons, which are modified
plastmats much like Fujinon A lenses, and not dagor design. In fact, I was told by a
Schneider rep that the final Kern dagor lenses were discontinued because G-Clarons
were superior as taking lenses in every respect: coverage, sharpness, and high quality images all the way from close-up to infinity. Well, on the one hand I totally
agree with him, but ... there are those times only a dagor is a dagor!

[Dan Fromm]

Drew, this thread is drifting. I'll say it again, although both types of G-Claron work well as taking lenses, Schneider didn't sell them as taking lenses.

About Dagors, my friend Eric Beltrando has calculated their performance from published prescriptions. He's done the same for Boyer Beryls, which are very very similar; he's suggested to me that Boyer's designer Suzanne Levy-Bloch may have lifted the prescriptions from Goerz patents. Anyway, he calculates that the claimed coverages for f/6.8 dagors are wildly optimistic.

[Drew Wiley]

Dan - I still have official Schneider literature in my files advertising G-Clarons (newer style) as studio taking lenses, not for graphics. The specifications sheet, however, is very conservative, and give angles of coverage as if they were meant
for process or closeup work. That is why, when used for enlargement, I would prefer a relatively long G-Claron, like a 250, for 4x5, because you'll get the very best performance at the center of the field. But through testing I found that Apo-Nikkors
are actually superior for enlargement, provided one works within a certain
magnification range. My experience with dagor-design lenses is limited to the very
last of them, the Kern series. I owned both the MC and single-coated versions of the
14" length. The tangential MTF and closeup quality is certainly not as good as the
plasmat-derived G-Clarons or Fuji A's of similar focus length, nor is the coverage.
There are obviously other qualities I prize these lenses for, however, but none of
them relate to use for enlarging.