Rob - the thing about choosing binoculars is that it's incredibly personal.
Buying binos is like buying shoes - someone else can't easily pick out a
pair that will be comfortable for you.

The downsides to 10x include:
Increased weight
Increased shakiness of the image
Smaller field of view
Dimmer image and/or smaller exit pupil and/or reduced depth of field

For me personally, my hands are very steady, my arms are strong enough, and
my facility with aiming binoculars and finding the bird is great enough that
the first three are not a problem for me. For other people, one or more of
these downsides may make 10x either less desirable or completely impossible.

The fourth bullet point above can't be much more specific because, for the
designers, there are trade-offs involved. They can improve some of these
items (along with the field of view), but only at the expense of other of
these items.

Again, for me personally, I find I actually prefer a reduced depth of field,
so I was able to find a pair which is pretty good on the other two. That
works for me.

With all of the downsides, what's the advantage? Well, IF THEY WORK FOR
YOU, then 10x do give noticeably more magnification and a greater ability to
resolve details. I CAN see more details on distant birds (or smaller
details on closer birds). There are birds that I would not be able to
identify with 8x. Also, in general viewing, the 10x binoculars make all the
birds seem a bit closer, which can increase one's pleasure at viewing.

I therefore recommend that people TRY both the 8x and 10x versions of any
binoculars they are considering. You may well decide that the pair you like
best is an 8x pair. But you might find a 10x pair that feels as
comfortable, in which case you should give those serious consideration.

Any hard-and-fast rules of choosing binoculars are probably wrong... "10x
is best", "8x is best", "Buy the best glass you can afford", "You have to
spend a lot to get a decent pair", etc. About the only one that I've felt
really holds all the time is that an objective lens smaller than about 35mm
is simply too small, period. And therefore most compact binoculars really
don't work for birding. (Having said that, someone will probably chime in
to say how happy they are with some particular pair of compacts...)

== Michael Hobbs
== Kirkland, WA
== http://www.marymoor.org/birding.htm
== http://www.marymoor.org/BirdBlog.htm
== birdmarymoor at verizon.net

--------------------------------------------------
From: "Rob Blomquist" <rob.blomquist at gmail.com>
Sent: Thursday, January 07, 2010 8:51 AM
To: "tweeter" <Tweeters at u.washington.edu>
Subject: [Tweeters] 8x and 10x not a big deal?

> Seriously, so many are talking 10x I am amazed, my first pair was 10 and I
> was quite relieved to have 8x later.
> --
> Rob Blomquist
> Mountlake Terrace, WA
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> Tweeters mailing list
> Tweeters at u.washington.edu
> http://mailman2.u.washington.edu/mailman/listinfo/tweeters