Tweeters,

Given the evident lack of birds and abundance of comments on bins and
telescopes recently, I thought I'd add my two cents worth. This spring I
compared bins for about two months, looked at a bunch, and asked for comments
from about a dozen Tweeters. I have a two-page printout of my e-mail of the
results, but did not save it electronically, don't have a scanner, and don't
want to retype it. But if anyone saved it and wants to post it to Tweeters,
please do so. Or e-mail me and I can mail you a copy.

Here is a summary of my observations:

In the northwest, everyone recommended 10x over 8x. One person said going to
a 10x made a much bigger improvement in image quality than increasing the
objective size. However, the image will be more shaky until you learn to keep
them steady, but everyone thought that we bird at longer distances (ducks and
hawks especially) so the greater image size from the 10x was important.

Roof prism (looks like two parallel tubes) was favored over porro prism
because it is not as easy to knock out of alignment (a three-figure expense to
correct).

For me, by far the most significant issue was eye relief, the distance from
the eyepiece to the pupil of your eye which allows you to see the full view
through the bins. I wear eyeglasses, and by comparing bins I determined that
I need 17mm of eyerelief. Less eye relief than you need, and fuzzy black
shades the image in the bins from the sides. More, and the entire image can
go black when the bins are not precisely centered over your pupils. When
exactly correct, the image just simply jumps into view when you bring the bins
to your eyes. This is a great feeling.

Swarovski in general had the longest eyerelief. In addition, the eyecups
screw in and out allowing an infinite adjustment, rather than the usual
folding which is either all the way in or all the way out. This is a really
nice system. Although info from various sources was not always consistent,
here are the eye relief distances from the bins I compared: Swarovski 8x50
(21mm); Nikon 8x32 (20mm); Sw 7x42 (19mm); Zeiss 7x42 (19mm); Leica 8x50
(18.1mm); Sw 10x50 (17mm); Nikon 10x42SE (17mm); Zeiss 10x40 (16mm); Leica
8x42 (15.9mm); Leica 10x50 (14.6mm); Sw 10x42 (14mm); Leica 10x42 (13.9mm);
Leica 8x32 (13.3mm).

I highly recommend the high-quality glass. In line with this, I agree with a
common belief that you should wait to buy the best bins you can afford rather
than compromising now.

One way to catagorize bins by size of objective lens (the lens on the far side
of the bins from your eyes). Generally the objective is 50mm, 40 or 42mm, or
32mm. As a general rule, the larger the objective the more light and detail
visible. But, the larger objective makes the bins heavier. The 50mm
objectives all weigher about 41 oz. The 40 or 42mm weighed between 25 oz
(Nikon 10x42 SE) and 33.5 oz (Sw 7x42). The 32mm weighed 22 oz. Contrary to
popular opinion that roofs weigh less than porros, the Nikon 10x42 SE was
lighter than any comparable roof.

The Swarovski and Leica are waterproof; the Zeiss and Nikons are not. This is
more a long-term problem. Bins which are not waterproof tend to let in dust
or moisture over the decades, which degrades the image. Cleaning the internal
lenses costs hundreds of dollars, so a single cleaning may make up the entire
difference in price between a top-of-the-line bins and one not so expensive.

I really couldn't tell the difference in image quality among any of the bins
listed above.

One thing which is important but which I couldn't quantify is the depth of
field of the view; that is, when focused at any given distance how far in
front of and behind that focused distance will birds still appear to be in
focus. For closer distances this seems to be more critical. That is, when
focused at twenty-five feet birds five feet closer may not appear to be in
focus, but when focused at 100 feet a bird at 95 feet will be in focus. If
you are looking at close birds, you may be constantly adjusting the focus.
How much more you may have to focus one kind of bins than another is
important, but I couldn't find any information available.

I am not sure the field of view is that important. When looking at a sitting
bird you naturally put the bird in the center of the image. Very little
practice is necessary to find the bird through the bins once you see it in the
field. Only if you look at flying birds like swifts or swallows, or search
trees through the bins to find hard-to-see birds, would a greater field of
view be important.

How closely the bins focus seemed to depend on objective size and
magnification. The smaller objective allowed closer focus (Nikon 8x32 to 8.5
feet), as did a lesser magnification (Zeiss 7x42 to 11.5 feet).

I agree with others that the Nikon 10x42 SE is simply an awesome binocular.
It is light weight, gives a great view, has good (17mm) eye relief, and I
don't mind the porro prism design. It is less expensive than comparable bins,
too. The only drawback is that it is not waterproof. I understand Nikon has
new roof prisms, in 8x or 10x42mm which are waterproof and have screw-in,
screw-out eyecups, but I haven't seen a pair nor do I know how much they cost.

I've looked through Swarovski 10x50 for several months now, and really like
them. I don't spend hours looking through them, so I don't mind the weight
(you can buy an attachment to mount them on a tripod if you really were going
to spend hours, say doing a hawk count, without putting them down. I do
notice that I must adjust the focus a lot a close distances. I got them more
for long distance birding where I don't have to change the focus, however,
rather than looking at our feeder.

A good place to find additional information is A Better View Desired, at
"http://www.biddeford.com/sing/BVDHome.html".

Eric Stahlfeld
Burien, WA