What To Know When Buying Binoculars
Chuck Fitzgerald. All Rights Reserved.
We are asked nearly every day: "What are your best binoculars?"
And every day we answer: "How do you plan on using them?" We are not trying
to be evasive with our answer, but the truth of the matter is – the best
binoculars for one purpose may be the worse binoculars for another. We want
you to Get It Right The First
Time.
Understanding your application is paramount in determining the best fit –
for you. Although there are many other specifications and qualities which
determine the usefulness of binoculars, we will discuss in this article the
primary characteristics for
determining the best fit for your application. But before we show you the
list, we should go over some basic terminology.
What do the numbers on binoculars mean?
All sporting optics (binoculars, spotting scopes, night vision goggles,
etc.) use the same nomenclature to describe important features. As an
example, a pair of binoculars may have 10x42mm listed as a technical
specification.
But what does this mean? The "10" refers to the magnification power of the
binoculars – that is – objects viewed will appear to be 10 times closer than
when they are viewed by the naked eye. The second number in our example is
"42mm." This refers to the diameter, in millimeters, of the objective lenses
on the binoculars. The objective lenses are located on the end of the
binoculars furthest away from your eye when viewing. As with the aperture of
a camera lens, the size of objective lens determines the amount of light
that can enter your binoculars. If your binoculars are going to be used
during low light (hunting and astronomy are good examples) you had better
have large objective lenses.
Another important number describing binoculars is called field-of-view. A
field-of-view of 390' indicates that the width of the sight picture is 390
feet at a distance of 1000 yards. Field-of-view is determined by
magnification and the focal lengths of the objective and eyepiece lenses.
More magnification always means less field-of-view. This specification is
sometimes expressed in degrees. A field-of-view of 6.5 degrees equates to
341' (6.5 times 52.5 equals 341).
How well your binoculars will serve you in low light conditions is described
as Twilight Performance. Although many things, such as overall design and
quality of glass impact this specification, magnification and objective lens
diameter are the chief components. A quick way to determine the Twilight
Performance of binoculars is to multiply the
magnification power (first number) times the objective lens diameter (second
number). The higher the result, the better the Twilight Performance. As an
example, 10x42mm binoculars will have better Twilight Performance than
8x50mm binoculars (420
versus 400).
Now that we understand some basic terminology, here is “What to Know When
Buying Binoculars."
* While compact binoculars weigh as little as a pound, by using them you
will undoubtedly sacrifice performance. If performance is your main
consideration, full sized binoculars are preferred. Anything weighing over
about 1.5 pounds will get heavy fairly
fast. Use a binocular support system to evenly distribute the weight across
your shoulders instead of using a strap around your neck.
* The amount of light available while using your binoculars will
determine –more than any other consideration – which binoculars are best for
you. Low light uses such as hunting, birding and astronomy require larger
objective lenses.
* The distance you will be from the object you view will determine the
magnification power required in a pair of binoculars. If your application is
bird watching, theater or
sporting events, a low powered binocular will suffice in most cases. But if
you're into astronomy, you'll need a high powered pair.
* The minimum focal point in binocular terminology refers to how near an
object can be to you and be still be viewed in focus. This tends to be
important for birding but not so
important for most other uses.
* Binoculars with a magnification power greater than 10x (and without a
stability feature) will be difficult to hold steady. This becomes important
when viewing the night sky or distant mountains. A tripod may be a good
thing to have if you’re using binoculars with high magnification.
* Using your binoculars outdoors will usually subject them to moisture.
Waterproof binoculars are preferred for all marine, hunting, birding and
other nature related activities.
* The greater the magnification, the narrower the field-of-view. If
field-of-view is important to you, don't purchase the most powerful
binoculars you can find. This becomes very important when viewing objects
that move quickly such as antelope, race
horses, shooting stars or race cars.
* As with almost everything else in life, with binoculars you get what
you pay for. There
are binoculars that cost under $10 and others which cost in excess of
$2,500. My experience says you will need to spend at least $250 for a pair
of binoculars worth having.
* There is no such thing as “one-size-fits-all” when it comes to sporting
optics. If you have multiple uses for binoculars, you will most
likely end up with multiple pairs of them – and that’s O.K.
Your understanding of these few simple tips will not only help you in
acquiring the correct binoculars for your application, but they will also
help you with successful viewing – no matter what you’re looking at. Use
this information and you’ll Get It
Right The First Time.
Get Outdoors!
About the author: Chuck Fitzgerald is the President of Arizona based
BackCountry Toys, an online store providing backcountry specialty gear and
educational information for outdoor enthusiasts. Visit
www.BackCountryToys.com to
receive the free newsletter "FreshAir” or call (800) 316-9055.
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