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You've decided that you've done without binoculars long enough,
have you? Good. If you choose your first pair of binoculars well,
you'll never regret your decision. But there's a catch. It can be hard
to choose well. Finding the perfect pair of binoculars is every bit as
difficult as finding the perfect boat, and the range of choices is, if
anything, even greater. The Fall 2000 Cabela's catalog, for example,
devotes seven pages to binoculars. That's more space than they give to
sleeping bags!
Still, selecting a good first pair of binoculars needn't be
impossibly hard. Binoculars are tools, after all, and the first
question you should ask yourself in buying any tool is this: "What job
do I want it to do for me?" You wouldn't try to bone a chicken with a
bread knife, would you? Or fish for brookies with a 15-foot spey rod?
Match the tool to the job. That's the first rule.
So, how will you. use your binoculars? If you're like most
paddlers, you'll want binoculars for one of three things: (1) wildlife
observation and bird-watching, (2) on-water navigation, or (3) what I
call Micawbering, after the charming if somewhat feckless character in
Dickens' David Copperfield. "Micawbers" simply want binoculars
which are light and easy to carry—binoculars to take along on the
off chance that something worth seeing will turn up.
Let's look at wildlife observation and bird-watching first, since
these are perhaps the most common uses to which binoculars are put. If
this is how you plan to use your binoculars, you'll find that the
requirements are more or less straightforward. You'll want binoculars
with relatively high magnification, a good field of view, and a bright
image. Since birds and other wildlife seldom hold still for long,
you'll also want to be able to focus the binoculars quickly.
OK. What's "relatively high magnification"? Let's say seven to ten
power. (Binoculars are usually identified by a pair of numbers, e.g.,
10 x 40. This is pronounced "ten by forty." The first number tells you
the magnification. The second gives the diameter of the objective
lenses—they're the big lenses at the other end of the binoculars
from the eyepieces—in millimeters.) Oddly enough, your ability to
see fine detail isn't determined solely by magnification. Optical
quality matters, too. But magnification is important. A
ten-power glass effectively brings a loon swimming 100 yards away to
within 30 feet of your canoe. That's the difference that magnification
makes.
Field of view is important, too. That loon looks pretty small out
there, 100 yards from your boat. Once you bring your binoculars up to
your eyes, you don't want to have to hunt all day for her. You want
her to be right there. So you'll want to see as big a piece of
real estate as practicable through your binoculars. How big is
"practicable"? Easy. Good binoculars will show you a circle with a
diameter of around 300-400 feet at 1000 yards. That's a reasonable
benchmark to shoot for.
Of course, it's sunlight that makes it possible for us to see. So
it's important that binoculars capture as much light as they can, and
the bigger the objective lens, the brighter the image—all other
things being equal. Unfortunately, the higher the magnification, the
larger the objective lens needs to be to give a bright image. Sounds
complicated? It is, but luckily there's a simple rule of thumb. For
wildlife observation and bird-watching, look for binoculars whose
objective lens diameter (measured in millimeters) is between four and
five times the magnification. A seven-power binocular with a
35-millimeter objective lens meets this test. One with a 15-millimeter
objective does not.
Rapid focus is the last criterion. You want to be able to adjust
your binoculars quickly and keep them in focus easily, even when your
target is as fast-moving as a diving kingfisher. (Not for nothing do
the Brits call serious bird-watchers "twitchers.") In practice, this
means that you want your binoculars to have what's called "center
focus": a single, central wheel or slide is used to adjust the focus
for both eyes simultaneously. Good center-focus binoculars will also
have an independent adjustment on one eyepiece, permitting you to
compensate for any difference between your eyes. This is a
one-time-only adjustment, however. You make it just once, and then you
can forget it. Center-focus binoculars were formerly harder to
weatherproof than binoculars in which each eyepiece is focused
independently—so-called "individual focus"—but this is no
longer necessarily true. Today, some center-focus binoculars are even
guaranteed to be completely waterproof.
Talk of waterproofing brings us to the second usage category:
on-water navigation. While most sailors keep a pair of so-called
"marine binoculars" aboard their boats, largely to help them identify
channel buoys and day-marks, few canoeists or kayakers feel the need
to purchase binoculars solely for this reason. Those who do should pay
special attention to waterproofing and field of view. They won't need
(or want) high magnification. A wave-tossed kayak isn't a very dry
place, after all, and it's hard enough just "picking up" a buoy or
day-mark with binoculars as your boat rolls and pitches, let alone
keeping it in sight. Under such difficult conditions, a pair of
individual-focus 6 x 30 marine binoculars will be pretty close to
perfect—if you can find them, that is. Most marine binoculars
sold today are 7 x 50s, and they're far from ideal for paddlers. In
addition to the fact that the magnification is really too great for
small-boat use, many 7 x 50s are too heavy and bulky to be managed
easily in the cramped confines of a kayak cockpit. Under the
circumstances, the best solution for sea kayakers may well be a
waterproof monocular. These needn't be spartan. One popular 5.3 x 30
monocular incorporates a rangefinder, a chronometer, and even a
fluxgate compass! It's a gear-head's dream come true.
The needs of Micawbers are less demanding than those of either
bird-watchers or navigators. If, like many of us much of the time,
you're neither adding to your life-list of exotic species nor crossing
the open ocean, then you're probably a Micawber. You want to have a
pair of binoculars with you in case something turns up, but you don't
need a specialist's tool. This being the case, you'll prize
compactness and light weight above all other things. Look for
binoculars with magnifications in the six-to-ten-power range, with
objective lenses whose diameter (in millimeters) is at least
two and one-half times the magnification. Happily, there are any
number of small binoculars that fit the bill. Here, too, you may find
it worthwhile to consider a monocular. If that's what you decide on,
don't feel that you have to apologize to anyone for having only half a
binocular. Read Dangerous River. There's never been a more
enterprising canoeist than Raymond Patterson, and he took a monocular
to the Nahanni. I doubt that he ever regretted his choice.
Whether you're a twitcher, a navigator or a Micawber, however, once
you've decided how you'll be using your binoculars, you'll need to
choose a pair that fits. Surprised? You shouldn't be. Binoculars are
extensions of your eyes. They have to fit well to work. In fact, the
fit of a pair of binoculars is at least as important as their optical
quality. If your binoculars don't fit, you won't use them. And
binoculars that aren't being used are just expensive paperweights.
In deciding whether or not a particular pair of binoculars fits,
two things matter most: interpupillary distance and eye relief.
Interpupillary distance is simply a fancy way of saying "the distance
between your eyes." Most binoculars will fit most people, but folks
with unusually close- or wide-set eyes will find it hard to get a pair
of binoculars that can be adjusted to suit them. This is a particular
problem with some roof-prism models. These binoculars—you can
identify them by their straight barrels—don't close down as
completely as do older, porro-prism designs. The result? People with
close-set eyes can't bring the barrels close enough together to see a
single circular field of view. (Despite what you've seen in the
movies, where the view through binoculars is almost always shown as
two adjacent circles, when you look through a properly-adjusted pair
of binoculars you only see a single, circular field.)
How do you know if the pair of binoculars you're thinking about
buying can be adjusted to fit? Simple. Try them out. That's easy to do
if you're in a shop. If you order a pair out of a catalog, however, be
sure you can return them if they don't suit you.
If you wear glasses—and you will, sooner or later, however
good your vision is now—you'll have to consider the second
element of fit: eye relief. This is a measure of how close you have to
bring your eyes to the eyepieces to see the full field of view. If you
wear glasses, you'll want at least 14 or 15 millimeters of eye relief.
Sometimes you'll find this number mentioned in the manufacturer's
specifications, but whether it is or not, you'll want to "road test"
any pair of binoculars you're thinking about buying. If you can't see
the full field of view when you're wearing your glasses, look
elsewhere. (In making this test, be sure to turn down or retract any
rubber eye-cups—and then be sure to turn them up again before
lending the binoculars to a friend who doesn't wear glasses. You'd be
surprised how oily eyelashes are, and oily streaks don't improve the
optical properties of eyepieces!)
When you've satisfied yourself that you can see the full field of
view through your new binoculars, take them for an extended test
drive. Go outside on a dry day—you wouldn't expect to return
binoculars that had been soaked in a rain storm or splashed by salt
spray, would you?—and use them for half an hour or more. Focus on
the far horizon, and on the side of your house. Try to pick up a hawk
(or a pigeon) in flight. If the moon is visible, as it is during
daylight hours for more than one week in every month, explore the
lunar landscape. Look at anything and everything that you can see,
near and far. Everything, that is, except the sun. Never look at
the sun with binoculars, even for an instant. If you've ever
started a fire with a burning glass, you'll have seen what the sun's
concentrated rays can do to your retina. Your sight is too precious to
risk.
After using your new binoculars for at least half an hour, take
stock. Have you had any trouble holding them steady or adjusting the
focus? Has the image ever been less than crisp and bright? Have you
noticed a headache or other sign of "eye strain"? If the answer to all
these questions is no, then you've found a pair of binoculars you can
live with. If you've answered yes to even one question, however, your
binoculars have failed their most important test. Return them to the
seller immediately and try another pair. Whatever you do, don't try to
talk yourself into keeping them, and don't be influenced by the
brand-name or someone else's choice. Buy the best binoculars that you
can afford, of course, and listen to the recommendations of friends
and "experts," by all means—but pay most attention to your own
feelings. Buying binoculars is like buying shoes. Only you can tell
when you've got a good fit. Once you have, though, you'll know it.
Then you'll be ready to embark on a life-long voyage of discovery
through a world that's suddenly become larger, brighter, and
infinitely more interesting.
Copyright © 2000 by Verloren Hoop Productions. All rights reserved.
Impedimenta
The Far-Seeing Eye: Binoculars for Paddlers (Part 2)
By Tamia Nelson
©Copyright 2007 Paddling.net, Inc. (View Privacy Policy)
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