Using a 9/240 G-Claron as enlarging lens

[Philippe Grunchec]

At which (best) aperture should I use this lens to enlarge my 8x10 negatives?

[ic-racer]

I'd think that at 1x to 2x (up to 16x20) you could use the optimum aperture that Bob may give us for that lens (I'm guessing its f22, but I don't know where to find the MTF data for that lens).

For bigger magnification, I'd think you might need to stop down more to keep the edges sharp because the field won't be as flat at big magnification.

[Philippe Grunchec]

If f22 is the best aperture for the G-Claron when used as a taking lens, is it the same as an enlarging lens?

I also have a Nikkor 210, but I wonder if it would cover 8x10. Any idea?

[ic-racer]

I use a Componon 210mm for my 1:1 projection printing, but if you need any magnification, you will run out of image circle with the Nikkor 210.

[Drew Wiley]

It works decently - better than some enlarging lenses, but not as well as the very best. From f/16 down, the degree of magnification is relatively flexible, so-so at f/11.
But that's the problem - it's going to be a lot slower than a dedicated enlarging lens.
I assume you're referring to a G-Claron taking lens and not a repro or WA version.

[Dan Fromm]

Phillipe, Drew, please see http://www.schneiderkreuznach.com/archiv/pdf/gcn.pdf

To summarize, G-Clarons weren't made to be used as taking lenses, although they can be, per Schneider, at f/22. Optimized for 1:1, intended for use between 1:5 and 5:1.

Phillipe, if you have the lens why don't you waste a little paper asking it how it performs? You'll have more confidence in the knowledge gained that way than you will in anything anyone here tells you.

Cheers,

Dan

[Drew Wiley]

Dan - G-Clarons were marketed extremely conservatively. Although the brochures highlighted their use for tabletop photography (not copy work), they actually excel in
most photographic applications, better than standard lenses, provided one doesn't need a fast lens. Repro Clarons without shutters were marketed for copy cameras.
I have tested them for enlargement use. Optically they are fine for this, just slow;
not in the league of an Apo-Nikkor or Apo-Rodagon, but better than a Componon S,
for example. You really can't see the difference except under a magnifier.

[Kevin Crisp]

The el-Nikkor 210mm will cover 8X10 on my Beseler cold light head, if that is what you mean by the Nikor 210. It is a big lens and may require some custom work to mount to some lens boards.

[Dan Fromm]

Drew, I've tried three out dagor type 240/9 G-Clarons as taking lenses and sold them. Sold not because they performed poorly -- they're great as taking lenses -- but because there was no inexpensive way to adapt one well to my gear. There are other 240 mm lenses that are easier to use in my situation. I have a 210/9 dagor type G-Claron that I haven't decided what to do with. A little easier to use than the 240s, not much, if any, better than other 210s I have and use. I've had a 150/9 plasmat type G-Claron that I thought marginally worse as a taking lens -- but with greater coverage -- than my 150/9 Apo Ronar, so it went. Many people use both types of G-Claron as taking lenses.

But that doesn't mean that Schneider sold them as taking lenses or that there's any difference between one in barrel on a process camera and another in shutter on a view camera. That was my point, sorry I wasn't clear enough.

Cheers,

Dan

[Arthur Nichols]

I use one for enlarging 8x10 and 5x7. I agree with Drew it is better than my 180 Componon (Not S) for 5x7. I can see the difference under the grain magnifier.

[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.