On Wed, 10 Jul 2002 18:40:33 GMT, Paul Chefurka
>On Wed, 10 Jul 2002 17:16:09 GMT, d_ruether@hotmail.com (Neuman - Ruether)
>wrote:
[...]
>>(Even with all this, I still select lenses for sharpness,
>>sharpness nut that I have admitted to being... See:
>>www.David-Ruether-Photography.com/slemn.html for evidence of this.;-)
>How do you define "sharpness"? It's a fairly slippery concept that seems
>to get fuzzier the closer you look :-) Do you use an MTF style of
>definition, pure resolution, or something more subjective?
The name of the article at the URL referred to *is*
"SUBJECTIVE Lens Evaluations (Mostly Nikkors)" for
a reason...;-) And the evaluation numbers are mostly
based on degree of detail-rendering over the great
majority of the frame at the first stop for which
good performance can be expected for the lens type
covered (that info is at the category headings for
the lens types, and the general characteristics of
the types are described in the text at the beginning
of the article). "Real" subjects are used for evaluation,
rather than test charts, since I feel the results
correspond more closely with experience in shooting
with the lenses. Both infinity-focus subjects (which
minimize focus and alignment errors compared with
charts, and which test at "real" distances, where
lenses often perform differently than they do at
"test" distances) and 5' subjects are used (many
lenses perform differently at these two distances).
Lenses that get a rating of very near "5", or even
a bit more are the ones that exceed the best
expectations for the category, and are sharp to the
corners wide open, without distance restrictions.
There are a few of these... Since I often have tried
multiple samples of a lens, I also show the approximate
rating variation I found. Some lenses vary a lot in
performance with varying conditions, and I indicate
that, also - and add comments to supplement what is
covered in the general comments at the beginning of
the article. All the Nikkor SLR *optical types* are
listed (I do not separate barrel types, so if the
optical construction of the MF lens is the same as
for the AF version, I do not separately list these,
for instance...) - and I also rate other than Nikkor
lenses that I have tried that were roughly in the same
quality range as Nikkors (ignoring the many yucky
lenses I have also encountered, some by "respected"
makers...;-).