I will be grateful for input on the following: I need a new lens to replace my 20yr+ fungus damaged 105 Companon-S.

My enlarger has a 105mm condensor. I need the very best in sharpness/definition from my 6x7 negatives. Mostly 16x20" enlargements. I may do some Ilfochromes in the future.

I had the 105mm APO Rodenstock in mind.

Apart from longer exposure times, would quality suffer if I use a 80mm or 100mm with the 105 condenser? Schneider or Rodenstock? (Schneider makes a 100mm) What is a good focus finder without unneccessary bells and whistles? I am only interested in ultimate sharpness from my high quality negatives. Any other suggestions in improving sharpness at the printing stage would be most wellcome. (I have a very sturdy enlarger)

Chris

-- Chris Hattingh (chriskimhattingh@aol.com), October 25, 2001

Answers

I can't speak specifically about the Rodenstock APO 105mm, but I had a Rodenstock APO 50mm with which I was very disappointed. I don't know if I just got a bad sample, or if my lens was indicative of the line, but it surely was not worth its appreciable pricetag.

I think the most consistently fine enlarging lenses are the Componons. I don't think you'll go wrong with a 100mm Componon.

Incidentally, I talked to the Schneider VP in charge of the Componon line at last years Photo Expo in NYC, and he told me that the Componons were in fact APO lenses, in terms of correction of chromatic abberation. The other thing is, if you poll professional labs, you will see a stong predominence of Componons. That alone should tell you something.

The other things to consider, perhaps even more important than lens brand, is getting the enlarger perfectly aligned and holding the negative flat. A glass carrier, while admittedly troublesome, is the only way to really ensure edge to edge sharpness.

-- Ted Kaufman (writercrmp@aol.com), October 26, 2001.

Hi Chris,

I have a 50mm APO-Rodagon (for 35mm) and a 80mm APO-Rodagon (for 6x7!) and I'm very happy with both lenses. I took the 80mm and not the 105mm, because I want to make 16x20 prints and the length of the "pillar" (I hope this is the correct word) on my Durst enlarger is not infinity. These lenses are very sharp, up to the edges ...

So, I can warmly recommend the APO-Rodagon lenses !!!

Tom

-- Tom Barth (tom.barth@gmx.ch), October 26, 2001.

While this is really a printing forum question, we seem to be doing a good job of handling it here, so I'll throw in my 2¢ worth as well. MTF curves are readily available for both lines of lenses from their manufacturers. Of the APO models, I personally prefer Rodenstock in the 50mm length and Schneider's 90 in the 100mm category.

The f/4.5 90 is really pretty amazing, delivering its best performance at f/5.6. That enables higher sharpness than a lens that has to be stopped down to f/8 or f/11 (see Ctein's book Postexposure) and shorter enlarging times--especially handy doing 16x20s with a slow paper or denser negative.

The worst of these lens options is, however, wonderful. Best wishes.

-- Brian Hinther (brianh@onewest.net), October 26, 2001.

I'm only printing B&W and doing color digitally. I've been using a 80mm El-Nikkor for 6x7 with great edge-to-edge sharpness. But for 16x20's I have found that I need a glass negative carrier to insure the edges being critically sharp. FWIW.

-- Gene Crumpler (hassieguy@att.net), October 29, 2001.