I want to buy either a Leica Duovid 8+12 binocular, a Swarovski 8.5X42
or a Leica 8X42 Ultravid.  Weight is not an issue for me, and neither
are the body styles.  I'm primarily interested in the relative
sharpness of the three, but only if there are significant differences
between them.  For example, I would accept a Duovid for its dual
magnification capabilities if, for example, it was only slightly less
sharp (say, 6-8%) over the fixed magnification ones.  In another
words, if the slightly less theoretical sharpness was not really
evident when put to use in the field. Without resorting to the
brochures put out by the firms that make them (since they could be
biased), please find objective values for sharpness.  Also, I distrust
much of what is said on the Internet since those reviews are usually
subjective, but if a scientific and indenpendent site or sites exist
that give valid values, you could mention them as part of your answer.
 The best information would be independent resolution values conducted
by a third-party.  I need to know the degrees of sharpness to a high
degree so that I can make a good decision.  Information on relative
contrast, and to a lesser exent, brightness, would also be a big help.
Finally, given what you know about my preferences, you might wish to
recommend one of the three.  Thank you.

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Request for Question Clarification by omnivorous-ga on 15 Oct 2003 07:00 PDT

Stevebio --

I've read similar analyses in Practical Sailor, a boating consumer
review, and one of the points that they make is that different
sharpness and brightness numbers depending on whether use is daytime
or nighttime.

Can't help you with this choice but it magnifies the difference
depending on lighting.

Best regards,

Omnivorous-GA

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Request for Question Clarification by jbf777-ga on 16 Oct 2003 11:40 PDT

I've talked to one of the manufacturers as well as another source
regarding third-party, objective/scientific analysis of binoculars. 
Looks like this kind of thing doesn't exist.

One of the individuals I talked with said essentially that all 3 are
very close. The Swarovski might be a little sharper.  The Duovid is
heavier.  Even if objective analysis was available, the marginable
differences would still have to be perceivable by you, since everyone
has different taste and eyes.  This is often the case in very high end
products, for example, microphones.  They all pass a certain level of
"professional quality" after a certain price point, and you start
getting into the "law of diminishing returns" -- where the more money
spent only equals marginal performance differences.

I have found a company that would allow you to buy 2 of them and
return the other within 30 days.  I could find another company that
has a similar policy, where you could buy the third and return it if
you choose to.

This would give you the most accurate, personal, real-world assessment
of these products, when they're in your own hands.

I could augment this with some reviews.

Would you be interested in something like this as an answer?

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Clarification of Question by stevebio-ga on 19 Oct 2003 06:54 PDT

I appreciate the good idea you have about having a company send me
both binoculars, and then having me decide which is best for my
purposes.  That may be a good idea, but before we head off in that
direction let me recheck to see if there is a dealer in the D.C.
(which I am close to) that has both pairs for me to look at.  If so,
it might be a slightly easier way to go. I'm disappointed that
independent scientific specs. aren't available, and rather surprised
since all of the competiting scientific instruments I've dealt with
have such data available.  I know it really doesn't matter, probably,
in a practical application, but I still wanted to know what the
differences are.  An independent (or retired) optical engineer might
have such info., or know how to get it.  I know, for example, that
microscopes, especially the research grade types, are tested
extensively, and of course, there is a lot in common between
microscopes and binoculars, in terms of aberrations, the quality of
glass used, coatings, etc.  I bought a Nikon microscope based on
independent reviews of several brands (it wasn't the very best, but
the law of diminishing returns that you mentioned applied there too,
so I went with the best I could afford.  Judging microscopes is
particularly important because, even though one's eyes may not tell
much (or any) difference, photographs taken with them can certainly
vary.  Interestingly, some binoculars as well as a whole lot of
spotting scopes, can also be used with cameras.  Mull over the above,
if you would, and yes, I would be interested in the reviews you have
found.