In 20x enlargements from images shot with the PC Super Angulon-R (28mm)I see some chromatic aberration in prints from Fuji color negative film, NPS--that is, there are red and green edges of things (red on one side, green on the other). Could it be due to the enlarging lens? Should I have stopped down more than I did? Martin Krieger krieger@usc.edu

-- Martin Krieger (krieger@usc.edu), September 14, 2001

Answers

This is a lateral chromatinc aberration, which won't improve if you stop down. Hard to say whether it's from the enlarging lens or the Super-Angulon-R, though I suspect the former if only because lateral chromatic aberration is typically more difficult to eliminate in a longer lens than in a shorter one.

-- Doug Herr (telyt@earthlink.net), September 15, 2001.

I used to own 3 Canon USM wides--a 14mm f/2.8 L, a 20mm f/2.8, and a 28mm f/1.8--and I was extremely surprised and disappointed to find that they all suffered from chromatic aberration. Stopping down didn't help. The only remedy I found was a program called Picture Window Pro 3.0, which allowed me to correct for this digitally.

-- Peter Hughes (ravenart@pacbell.net), September 15, 2001.

I use Quantum Mechanic Pro, a PShop plug-in. Works well in correcting abberations and reducing noise introduced by scanning.

-- Andrew Nemeth (azn@nemeng.com), September 15, 2001.

Martin

It think you need to check your enlarging lens in the first instance. I would not expect the PC SA to show this kind of fringing, especially at only 20X. If you really want to know, I think you can call or email Leica in their techincal dept. I think you would get a more accurate answer if you called/emailed Solms. This is the kind of thing they can tell you. If it is not to be expected then the lens needs fixing.

I have the 21mm SA which I assume is a similar lens and although it suffers from spherical abberation I have not noticed chromatic effects.

Personally, I suspect it is the enlarging lens - what was it?

-- Robin Smith (smith_robin@hotmail.com), September 17, 2001.