Now, here's an excerpt article by FLAAR concerning Rodenstock digital lenses:
More about them at:
www.digital-photography.org
"Rodenstock digital lenses":
"What lens should you use for professional digital photography? Can you use a regular (traditional) lens or do you need a special digital lens?"
"Rodenstock has taken a lead in the recognition of the special requirements of advanced digital systems. Linear digital systems scan red, blue, and green colors separately. If the lens focuses each color differently, the end result will be out of register. This failure was previously considered "corrected" if the error was small. But Mike Collette, Better Light, recognized quickly "that even the best lens designer is going to have a painful surprise when people start looking closely at enlargements of digital photographs." The slightest enlargement shows red, blue, and green lines clearly not overlapping, even with the highest regarded German lenses. I do not list the lens manufacturer by name since they had no way to know about the capability of digital resolution when these lenses were designed years ago. Besides, both of the top lens brands suffer the same optical situation.
If you select an APO lens you can correct considerable problems. Both Michael Collette, inventor of the Better Light digital system, and Steve Johnson, professional photographer specializing in digital panoramas, each suggested to me that I try APO lenses. My normal Macro lens was a Schneider 180mm Makro-Symmar which had faithfully served me for thousands of 4x5 photographs on film. The Rodenstock brochures I had in the USA did not list any APO lens in the macro range (most of my photography is of archaeological artifacts and I tend to use macro lenses for them). Thus it was a pleasant surprise when Dr. Rascher indicated that Rodenstock did indeed have an apochromatic macro lens, as well as a variety of lenses appropriate for digital needs.
Since virtual reality is a huge market for panorama photography, wide angle lenses are increasingly called for. Rodenstock offers a considerable variety in apochromatic format.
But be forewarned, do not trust cheap lenses from after-market companies in Asia. Many carry the apo-designation, but you get what you pay for, a cheap Asian knockoff.
The true apochromatic lenses for wide angle photography with high quality German optics would be the Apo-Grandagon series.
For the demanding requirements in other aspects of high resolution digital imagery, Rodenstock offers their Apo-Sironar-Digital, Apo-Macro-Sironar, Apo-Sironar-S, Apo-Rodagon-N, and Apo-Rodagon-D series of precision optics.
Since FLAAR. is oriented towards scientific photography, we might also mention the Rodenstock series of highly specialized macro lenses for CCD cameras. Rodenstock offers reproduction ratios from 1:7 to 8:1."
Now, here's a blurb from the Rodenstock site:
"Apo-Sironar Digital & Apo-Macro-Sironar Digital LF lenses:"
"This line of lenses provides the photographer with an exhaustive spectrum of focal lengths for digital shots in the very highest imaging quality with adjustable professional cameras. The fine gradation meets the demands of every motif situation and all chip and scanner formats. Focal lengths from 35 mm mean that real wide-angle shots are possible even with the smaller chip sizes while still allowing large movements. All Apo-Sironar digital lenses are characterized by excellent sharpness and brilliance together with total freedom from color fringes in real apo quality."
NOTE: the last line: "Real APO Quality"
So, based upon the statements by Mike Collette of Better Light, and Rodenstocks reference to "Real APO Quality", it seems that the further refinements of APO corrections for these lenses where triggered by the specific demands of digital imaging.
Of course they can also be used with film. I don't think anyone thinks they can't unless they are lenses with a smaller coverage.
