----- Original Message ----- From: "Elias_Roustom" <elroustom@xxxxxxxxx>
To: <rollei_list@xxxxxxxxxxxxx>
Sent: Sunday, August 01, 2010 2:37 PM
Subject: [rollei_list] Re: Lens recommendation
So does that mean the non-APO designated Rodagon's are just as good?
E.
Its hard to really know. Rodenstock makes its enlarging lenses for
different magnification ratios, I don't think anyone else does that.
In theory a lens with non-moving elements can be corrected for
spherical aberration and astigmatism at only one object distance. The
correction may stay very good at other distances but for very critical
use its best to have a lens which is specifically designed for the
application. This has nothing to do with the APO designation, which I
think Rodenstock uses as a sort of trade-mark for its premium quality
lenses. As I said they are not really apochromatic and the mis-use of
the term bothers me but the performance is outstanding nonetheless.
--
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx
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