Re: comparing lenses

[P3D Eric Goldstein <egoldste@xxxxxx>]

Cliff Mugnier wrote:

> In regard to high-quality 90"s lenses from Nikon, I have calibrated a
> number for photogrammetric applications since 1990.  A FORTRAN program was
> written to model the systematic radial lens distortion in a lens.  After
> the photos were taken with a 55mm Micro-NIKKOR lens


Yes, the 55mm micro-nikkor is a superb high resolution low distortion
lens. So is the Canon 50 mm f/3.5 macro. These, and comparable lenses
from Zeiss, Leitz and Schneider, represent the top of the line of lens
performance when using traditional quantitative measures. It should also
be pointed out that these are not common consumer grade optics. At best
the Janapese glass is about three times more expensive than common
standard grade lenses; the German glass much more than that.

At the risk of stating the obvious, in case anyone is wondering whether
one could construct a stereo camera using modern top-of-the line lenses
which outperforms 50's lenses in the areas of resolution, distortion,
apochromatism, etc, then wonder no further. The answer is *of course*
you can. Of course lens glass, design, fabrication, coatings have all
improved significantly in 40 years. My point is two fold: first, that
overwhelmingly, these technological advancements have been used to
produce cameras which are far less expensive (in adjusted currency) than
50's cameras and with high levels of miniaturization and automation,
generally resulting in instruments of high convenience producing images
of indifferent quality. Nikon and Canon are getting out of the business
of designing top end professional cameras and lenses because there is
virtually no market for them. The world wants P&S or cheap SLR zooms and
gets it; my argument is that these cameras will not make for improved
stereo rigs.

Second... I have made extensive subjective comparisons between belplasca
tessar and realist ektar and paragon images and images taken with with
Nikon and Canon macro lenses, as well as modern Contax (Zeiss) glass and
standard prime lenses from Nikon and Canon. I routinely hire
photographers to shoot projects for work, and I have asked them to
subjectively compare as well. Here's what we generally all come away
with, just our opinions...

The macros seem to exhibit visibly higher resolution when shooting
finely detailed objects. They also seem to have a somewhat "clinical"
appearance however and do nothing to flatter or romance subjects.
Sometimes this works and sometimes it doesn't. The modern standard
lenses are comparable to the vintage glass in terms of visible
subjective "sharpness," with the Nikon lenses being somewhat contrastier
than the Canon and vintage lenses. Quite often this enhanced contrast
leads to images which exceed the contrast range of the chromes. Both the
vintage glass and the modern primes exhibit good "soft" qualities of
image roundness and plasticity and dimensionality; this is often the
result of a small amount of lens distortion but is appealing none the
less! The classic lenses in particular tend to be more romantic and
evocotive and enhanse the emotional character of the shot... probably
inappropriate for medical or scientific photography!

IMO, it all boils down to studying and then using the characteristics of
a particular lens or camera as a tool to achieve the desired
photographic result. I accepting this approach, one camera is only
"better" than another in it's ability to achieve the particular image
the photographer wishes to achieve... 


Eric G.


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