Hi--

>>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...

>Thank you very much, it does help.

You're welcome!

>I seem to live dangerously, when as
>an amateur (albeit a keen one) I inadvertently "take on" people like
>your goodself or DR, whith their apparently professional knowledge of
>the subject.

Never hesitate to do so! We may (or may not ;-) clobber you - but we all
learn in the process of sorting this stuff out....

>Yet what bothers me are perahps the semantics and the
>philosophy of it all. I agree that if anyone were to count the number
>of neuron connections in someone's brain and how often they are "fired"
>he might arrive at a list of numbers, which would be objectively
>correct and factually true, but apparently meaningless and without any
>connection with the nature and quality of that person's thoughts.
>Equally, lists of objective numbers may not reveal the nature and image
>quality of a given lens, except perhaps for a few scientists.

Yes.

>Yet you
>yourself say in your posting, for example "Though I often find DR OK's
>lenses that I find beneath my standards", which to my mind can only mean
>that you do have, after all, an objective standard against which to
>judge those lenses.

Hmmm, more subjective... It is always a balancing act - if I make
absolute demands of my lenses' performance, I will use VERY few lenses!
From various posts, it appears that several lenses that I consider
well below the average of what I would consider fine, are considered
good by DR for his purposes (photojournalism, where having the ultimate
image quality may be much less important than other considerations
[size, weight, price, speed, ease-of-use, availability, etc.]), or for
those with obviously lower standards than mine or his (the many who think
28-200mm zooms are OK, for instance...;-).

>(In the second part of your above sentence you give
>DR the right to be indecisive, which to me would be a contradiction in
>terms, at least as far as the OKed lenses were concerned). In saying
>this I assume that we are at the level where one goes without bread, if
>necessary, in order to buy the best glass he can afford, rather than buy
>a mediocre lens, simply because it is cheaper.

No, again because there are no golden absolute standards. While, given
the choice between using a poor quality cheap wide-range zoom (or even
a pretty decent, but mediocre, wide-range zoom), and three top-quality
primes, I would choose the latter, but someone on a tight budget, or
who would substitute high image quality for convenience, may (reasonably)
make a different choice. (Though I may think the choice poor, if
someone puts a Promaster cheapo 35-70 on an F4 Nikon....;-)

>Semantically, it seems
>to me that your subjectivity goes only as far as establishing a number
>of preferred paramaters or standards for judging objectively a
>particular lens, eg, as you say yourself, you may prefer a colour
>neutral lens to a slightly sharper bluish lens. This must surely be all
>right as long as you tell your audience why the test is subjective, ie
>instead of saying the first lens is better than the second, full stop,
>you tell them I prefer the first to the second because I prefer a colour
>neutral lens, even at the price of loosing a little in sharpness. But
>in the end the colour neutrality and the bluishness of the respective
>lenses can probably be expressed in objective mathematical and/or
>physical terms.

Yes, but why? There are so many other aspects that are more important
than color balance (which is easily changed - I use four off-brand
lenses that are all cooler than Nikkors, and I use various skylight
filters to bring them near to Nikon-normal color). Juggling all the
performance aspects in a mathematically meaningful way is impossible - it
all MUST be subjective, in the end. Personally, I consider good contrast
and even center-to-corner sharpness at the apertures I want to use with particular lenses of primary importance - other aspects of lens performance are either considerably less important, or unimportant, unless they are so
bad that they interfer excessively with the ordinary use of the lens.

>Perhaps you would be kind enough to answer a question which preocupies
>me a great deal, because I am no longer sure whether I have succumbed to
>a myth, or whether this is an objective fact. I refer of course to the
>Leica versus Japanese lenses debate, in particular Nikkor lenses. Years
>ago I purcahsed some Leica lenses and equipment, and my feeling was that
>probably they belonged more to the colour neutral variety, whilst the
>Japanese, in particular Nikkor lenses, might belong to the slightly
>sharper but more bluish variety. I kept telling myself that the colour
>rendition of the Leicas was significantly more neutral and realistic,
>and, without wishing to sound too narrow-minded, nearer the
>European/American sense of colour, or that they were more artistic
>lenses, if I can use this term. Does your experience as a lens
>"checker" (to respect your terminology) support this view?

Hmmm, this week someone else made the same comparison between Contax
lenses and Nikkors, yet Nikkors are supposed to be "warmer" than Canon,
and they are warmer than many other brands I have compared them with.
Why not just add slightly yellowish UV filters (or the color of skylight
filters you like) to the Nikkors and be done with it...? ;-) What I have
noticed is that several of the Leica lenses I tried were not sharp enough
at the wide apertures I wanted to use them at for my taste... I also
noticed that some Zeiss medium format lenses I tried were distinctly
not what I would consider top-quality users. So, I tend to take the
"German lenses are better" attitude as yet another indication of the
power of mythology....;-)

>I have
>recently acquired my first LF, and the choice is now between Schneider
>and Nikkor. I heard so much praise lavished on the 90mm Nikkor SW 4.5
>that when I found it second hand (which is very rare here in the UK), I
>felt that I had to buy it. Yet, would a 90mm Schneider Super Angulon
>5.6 have been a more "artistic" or colour neutral lens than that
>Nikkor? Your views would be gratefully appreciated. Thank you in
>advance.
> Joseph White

Hmmm, I think you probably know what I think, from the above...
BTW, it appears that the f5.6 SA's have noticeable pincushion distortion
near the edge of coverage. The f8 SA's have poor illumination evenness.
The f8 Nikkor wides have exceptional coverage and illumination evenness
(the 90 almost covers 8x10, though not evenly). Color can be adjusted
with filter or film choice...
And BTW, if you have not seen "SLE(MN", it is at these sites:
-- Jan-jaap Aue: (nice text format)
http://www.phys.rug.nl/mk/people/aue/nikon/david.html
-- Quang-Tuan Luong: (nice text format)
http://www.cs.berkeley.edu/~qtluong/photography/35mm/nikon-neuman.html
-- Niklas Nikitin: (nice table format)
http://www.cs.hks.se/~nicke/private/photo/lenstest/david.html
-- Leo Verwoerd (plain text and table formats)
http://utopia.knoware.nl/users/leover/nikkor.htm
-- Bo-Ming Tong: (plain text format)
http://www.cs.arizona.edu/people/bmtong/nikon/c.html
(number 13 in table of contents)

(Will you give your permission to post the above? I think it might
be useful. Let me know. Thanks.)
David Ruether