In article
>In article <59l6tr$n5s@news.acmenet.net>, David Rozen
>
>>Chuck Whitaker (chas@mind.net) wrote:
CW:>>: Does anyone know where there's an archive of lens tests? I'm wanting to
>>: compare my Tokina 24-70 SZX with Olympus' 35-80/2.8. I know the Olympus
>>: has better optics, but I don't know how *much* better. Given the extra
>>: price, weight, etc. I want to know. Any ideas on where lens test data is
>>: available? Thanks to whoever can help.
DR:>> I suppose I am only one of a zillion to tell you
>> that the kind of comparison you seek cannot be
>> determined by any lens tests.
JW:>Why not? In particular with zooms? I am fully aware that the number of
>parameters to take into account is rather large, but it is still not
>infinite. I always read DR's contributions with great interest, and
>learn from them a lot, but he has a tendency to stay on the fence
>sometimes. I am certain that there is a way to arrive at an objective
>assessment of the quality of various lenses; that that assessment is
>accessible to an elite of experts and/or scientists; and that "ordinary
>mortals" should also have access to it, rather than indulge in
>meaningless generalities like "the best lens is the one you like" etc.
>I also suspect that various brands have their own personality (eg strong
>and less strong points), which could also be assessed objectively and
>comparatively.
As an undefatigable lens, ah, "checker" (I hesitate to use the word
"tester", since it indicates the use of very objective testing means,
with resultant objective conclusions - which I don't believe are easy
enough to use/achieve without truly exhaustive efforts, efforts that
are beyond the means of even professional testers to carry out with
sufficient thoroughness to guarantee meaningfulness), I think what
you are asking for does not, and will not, actually exist. I post my
"SUBJECTIVE Lens Evaluations (Mostly Nikkors)" with subjective
evaluation numbers (plus general descriptions of lens-type performance,
and particulars of individual lens performance when needed) for various
Nikkor and other lenses occasionally (and it appears on at least five
web sites). I know from this experience how difficult it is to compare
even two similar types of lenses from the same manufacturer (or even two
samples of the SAME lens!). Comparing two lenses of the same type and
approximately equal quality from different manufacturers with different
design priorities is useless - I may prefer uniform center-to-corner
sharpness by mid apertures to higher center performance at all apertures,
but with poor corner sharpness throughout (or I may prefer better
uniformity with focus distance changes than ultimately better performance,
but only over a short focus range [or I may prefer a color-neutral lens
to a slightly sharper bluish lens {or I may prefer optimizing sharpness
over optimizing distortion characteristics}]), ETC.!!! Though I often
find DR OK's lenses that I find beneath my standards, I think that he
is right in being indecisive - for many people and for many purposes,
mediocre lenses are useful and sufficient, and the price may be a factor.
(BTW, any of the major manufacturers could design and build lenses without
many detectable faults, but few of us could afford the prices - even the
top-end lenses represent sets of design compromises, but therefore it is sometimes possible to buy them....;-) I consider most chart-derived
lens "tests" to be close to useless (for various reasons) in predicting
how a lens will perform in real photo conditions, so I recommend avoiding
the alluring, but misleading, sets of lens "tests" so often assembled
and posted/published - the best test (though not easy!) is to try out
together the samples of the various lenses you are considering buying,
keep the ones you like, and return the others...
Hope This Helps