Chances are, you already own a pair of binoculars – a pair you inherited or bought without much thought; a pair that has served, but maybe did not excel. But now you are ready to move up to quality optics... binoculars that will make it easy to get into those hyperkinetic warblers and treetop vireos.

1. You are a person who enjoys watching birds and this C hances are, you already own
a pair of binoculars – a pair
you inherited or bought without
puts you in good company. much thought; a pair that has
In the estimates of the United States Fish and served, but maybe did not excel.
Wildlife Service, over 60 million North Americans have
discovered the pleasure and challenge of birding. But now you are ready to
move up to quality optics...
binoculars that will make it easy
to get into those hyperkinetic
warblers and treetop vireos.
Binoculars You need binoculars that are
sharp enough to resolve the
details that separate look-alike
For Birders flycatchers and bright enough
to disclose the facial pattern of
an “olive backed" thrush stalking
the shadows. In short you are
ready to buy a pair of “birding
For more nature habitat information binoculars."
Visit these helpful websites: Won’t Just Any Binocular Do.
Binoculars are the primary
A Plant's Home
tool for bird watching. Different
A Bird's Home “User Groups" (hunters,
A Homesteader's Home yachtsmen, backpackers,
concert goers) use binoculars
as an accessory to their
activity or sport. But binoculars
are not just an accessory to
birding.
Binoculars are the
instruments that define
birding – the functional
equivalent of the first
baseman’s glove, the
musician’s instrument, the
plow in the hands of the
frontier farmer.
Every user group has its own
peculiar needs and constraints
that binocular manufacturers
translate into binocular makes
and models.
Hunters, for example, demand
rugged, durable, optically precise
binoculars that perform well
even in the low light conditions
of dawn and dusk. Yachtsmen
© WindStar Wildlife Institute
Page 1 A Plant's Home

2. require optics that are If the binocular you are Roof prisms, which became
impervious to weather. considering is flawed in popular in the late ’60s and
Backpackers want optics that performance or design (i.e., ’70s are longer and sleeker in
are light and portable. they do not focus close design, with the objective and
enough…they do not fit your ocular lenses falling in
But birders demand all these hands…the ocular lenses alignment along the same tube.
attributes and more. For cannot be adjusted close
binoculars to be birder worthy, enough to offer a single Both designs have
they must not only be durable image…) do not buy them! If advantages and
and precise, but also you do buy them, you will only disadvantages. Because Porro
weatherproof and portable. replace them later. prism binoculars have fewer
They must focus fast and focus internal “elements" (lenses and
close. They must offer a FOURTH – There are very prisms) and more generous
generous field of view and cheap binoculars and very tolerance specs, they are
provide exceptional depth of expensive binoculars. There are generally brighter, less
field even at close quarters. binoculars that are good for expensive to manufacture, and
This article has one objective: birding, and binoculars that are less expensive to repair in the
to give you the information you not good for birding. event of a mishap.
need to choose true birder
worthy binoculars and spotting There are no good cheap Roof prisms, though more
scopes. birding binoculars. It takes expensive, also tend to be more
quality materials and rugged with elements more
Forewarned is Forearmed sophisticated engineering to firmly anchored within the
There are several things you craft birder worthy binoculars. barrels. Many people also find
should know even before talking Expect to pay a commensurate Roof prism binoculars easier to
to a salesperson. price – three to four hundred hold steady for extended
dollars at least. periods.
FIRST – As a bird watcher,
you represent the largest “user What Are Binoculars. Binocular Shape
The important thing about
group" in the optics market. Binoculars are twin barreled
binocular shape is how they feel
Over 30 percent of all telescopes whose barrels are
in your hands.
binoculars purchased are used aligned to fall on the same
for birding. spot. They are superior to a If you grasp a pair of
telescope insofar as they can binoculars and bring them to
SECOND – The needs and be used with both eyes open – your eyes and your finger does
constraints of birding are well making long-term viewing easier.
not fall comfortably upon the
known to binocular Since binoculars are usually focus wheel, or if you have to
manufacturers, but they might hand held, they are also more shift your grip to move the
not be known to the sales portable and faster to use than focus wheel, then the
person you deal with. telescopes. binoculars are poorly designed
or too large for your hands.
Chances are, after reading Binoculars are divided into Put them back on the shelf.
this article, you will know much two basic design classes:
more about birding binoculars Likewise, if you bring the
than any non-birding s Porro prism; and binoculars up to your eyes but
salesperson you will meet. Don’t s Roof prism. find that you cannot draw the
let them confuse you. eyepieces close enough to offer
Porro prism or “traditional a single image, put them back
THIRD – All equipment, binoculars" are wide-bodied. The on the shelf. The minimum
including binoculars, is designed big lens in front (the objective “interpupillary distance"
to compensate for a human lenses) and the smaller one in offered by some models is
short-coming. People should the back (the ocular lenses) are simply not close enough to
never be forced to compensate offset – i.e., not aligned along a accommodate people with
for their equipment. vertical axis. closely-set eyes.
© WindStar Wildlife Institute Page 2 A Plant's Home

3. Shape directly relates to how leather-type or guttapercha focusing binoculars. These would
easily and steadily binoculars covering. be fine, if birds never
may be held, and this directly approached closer than 50 feet
affects image quality. Focusing – which is about as close as
Birding demands binoculars permanent focusing binoculars
“Mini" binoculars, favored by that focus quickly. When can offer a clear image.
backpackers because of their attention is diverted from a
reduced size and weight, offer close-at-hand warbler, to a But as birders know, birds do
little to anchor a shake-free distant, fast disappearing appear closer than 50 feet. In
grip so birders generally avoid hawk, time spent spinning the fact, sometimes – in cattail
them. focus wheel to go the range of marsh, dense woodlands, or
focus is, well, time spent tropical forest, a bird might be
Large, bulky or “Marine" spinning your wheels. no more than ten feet away,
binoculars force users to hold and because of poor light or
their elbows high and widely A binocular that can go obstructing vegetation, an
spaced, decreasing stability from close focus to infinity identification cannot be made
and increasing muscle fatigue. quickly and smoothly is with the naked eye.
Birders avoid these, too. invaluable in the birding arena.
At times like these a
Binocular Weight Birding binoculars should be binocular that offers super-
Binoculars are literally a center focusing binoculars. This close focus may make the
weight around your neck. How means that by moving a well difference between a Life Bird
much you want to bear is up to positioned wheel, both barrels or a shoulder shrug – which is
you, but in general, 20-30 oz. is of a binocular are adjusted to say, all the difference in the
about as much as most people quickly and simultaneously. world.
care to consider.
An individual eyepiece Birding binoculars should be
The elements contributing to adjustment ring (or knob) is able to focus down to 15 feet.
the overall weight in a pair of available to compensate for Binoculars that offer a close
binoculars include: the small differences that focus down to nine or ten feet
exist between an individual’s are prized.
s the optical elements; eyes. It is set once – then
s the body; and never again. If you do a great deal of
s the outer covering. woodland birding, or watch
Some military or marine birders coming to your feeders
High quality optics, made of binoculars offer individual at very close quarters, close
barium crown glass (BAK-4), eyepiece focusing – a system focusing binoculars are a must.
are denser and heavier than that employs adjustable rings
optics made of the cheaper that encircle both ocular Magnification
boro-silicate glass (BK-7). The lenses. This system is slow, Binoculars come in different
quality of the image you see is cumbersome, and therefore, ill powers designated by the first
directly related to the quality of suited for birding. number of the binomial legend
the optics. etched on all binoculars
Some binoculars offer levers (examples: 8x30, 7x42, 10x42).
To reduce overall weight, instead of wheels for “quick
quality binocular bodies are focus." These are appealing in The second number refers to
cast out of aluminum or rugged theory but in fact require a the diameter of the objective
space age synthetics. two-handed grip and a bit of lens in millimeters and will be
dickering to get a sharp image. discussed in the section dealing
To help protect the internal They also tend to not be very with “Light and Brightness."
elements many binoculars are durable.
“armored" – covered with shock Simply put, a 8x binocular
absorbing rubber or Some manufacturers also (eight power) makes distant
polyurethane shell instead of a offer permanent focus or non- objects appear eight times
© WindStar Wildlife Institute Page 3 A Plant's Home

4. closer than they really are; a Almost all active birders use s Your hands are steady;
10x binocular makes the object binoculars that offer between 7x
appear closer still – ten times and 10x. What magnification you s Most of your birding is
closer. choose hinges on a number of conducted over great
considerations. distance and open spaces;
The tendency is to believe
that bigger is better – that the In general, lower magnification s You do not commonly include
more “power" a binocular has, is to your advantage if: a spotting scope in your
the better it will perform. This optical arsenal.
is not necessarily so and there s You are a beginning birder,
are several reasons for this. unpracticed at locating If you are still undecided
birds with binoculars; between 7x or 10x binoculars,
First, although higher consider a compromise – like
magnification will increase the s You are a birder having an 8x but NEVER BUY A ZOOM
size of a distant bird and difficulty holding higher BINOCULAR! They are optically
enhances the details that will magnifications steady; inferior and even at the lowest
be seen, increased magnification, offer a
magnification also magnifies s Much of your birding is comparatively limited field of
the effects of hand shake and conducted at close view.
heart beat. quarters – in woodlands or
rain forests, or from the If you look at the optic lines
The image may well be bigger deck of a moving boat; offered by the finest optical
but details, as measured by companies or if you look at the
image perception, will remain s You are a highly skilled birder instruments in the hands of the
essentially the same. more interested in speed finest field birders, you will never
than in seeing “field marks" see a zoom binocular. This
Greater magnification also of birds you recognize by should send a clear message to
results in a smaller field of view, their JIZ (general impression the discerning consumer.
a darker image, and a shallower and shape).
depth of field – all of which Light and Brightness
directly affect binocular Ten power binoculars get the Once – and not long ago; and
performance. nod if: not without reason – much was
Purchase Quality Binoculars
© WindStar Wildlife Institute Page 4 A Plant's Home

5. made about binoculars and that exits the binocular to fall The important consideration
brightness and light loss. upon the human eye. when buying binoculars is to
Guides to purchasing optics make sure the optics are “fully
expounded upon the mysteries This shaft of light, seen as coated" or, better still “fully
of the “twilight factor," and the bright dot swimming in the multi-coated." The operative
“relative brightness," and center of the ocular lens is word is “fully" because this
“relative light efficiency." Sales called the “exit pupil" and is means that all air to glass
people who know little about still an important surfaces both inside the
binoculars except, perhaps, how consideration when buying binocular and out have been
to read charts still expound optics. Here’s why. treated to reduce light loss.
upon these mysteries.
The human eye has a pupil, Different manufacturers use
Certainly a bright image, too – one that opens and different, patented names to
offering sharp contrast and contracts in response to light distinguish their coatings. The
accurate color rendition is conditions. In bright light it can important thing is to be sure
important to birders – in fact, expand to about 7 mm that all glass surfaces, inside
it is essential. The fact of the (depending on your age), thus and out, are single or “multi-
matter is that since the advent establishing the functional limit coated" to reduce light loss.
of coated lenses…and multi- of the binocular’s exit pupil –
coated lenses...and phase because any light falling The process used to coat
coated Roof prisms...all the old outside the maximum limit of binoculars lenses is exacting
rules governing glass and light the human eye serves for and costly. It accounts for
have been bent. nothing. much of the price difference
between quality binoculars and
If you are willing to pay the Beginning in World War II, it less expensive binoculars. But a
price for quality binoculars, was discovered that a coating commensurate price can also be
you are virtually assured of of reflection reducing material your assurance that your are
owning binoculars that offer (like magnesium fluoride) buying binoculars that are
superior brightness. applied to the surface of glass bright and sharp enough to
could reduce light loss caused perform in the field.
The problem used to be this. by reflection from 5% to almost
Every time light strikes polished 1%. This coating appears as a Field of View
glass (like a lens; like a prism) blue, or purple, or green glaze and Depth of Field
5% of it is lost, reflected away. on the lenses. Field of view is the measure of
In every binocular there are 10- the distance from one side of a
16 glass surfaces whose Later it was discovered that binocular’s image to the other
cumulative loss of light equaled by applying multiple, thin as seen through a stationary
about 50%. The net result was coatings instead of a single binocular.
a dark image. coating, light loss could be
further reduced to a mere This measurement, either
In partial compensation, fraction of 1%. inscribed on the binocular or
binocular manufacturers could included in the accompanying
increase the size of the Recently, several literature, may be designated in
objective lens. The size of the manufacturers of superior degrees of arc (ex: 6, 7); feet at
objective lens is measured in quality Roof prism binoculars 1,000 yards (ex: 415 feet at
millimeters and appears as the have begun coating the “Roof 1,000 yards); or meters at
second number of the legend prism" with a material that 1,000 meters.
stamped on binoculars compensates for the modest
(example: 7x42, 8x30, 10x50). wave length shift inherent in However the measurement is
the Roof prism design with the noted, a wide field – one that
Larger objective lenses allow result that “phase-corrected" offers no less than 6 degrees
more light to enter the Roof prisms offer the same of arc (or a minimum of 300
binocular, increasing the sharp image contrast found in feet at 1,000 yards) is
diameter of the shaft of light Porro prism binoculars. essential to birding.
© WindStar Wildlife Institute Page 5 A Plant's Home

6. A wide field makes it easier With rubber eyecups rolled down fogged binoculars upon the
to pick up and identify fast or otherwise retracted, swallow-tailed kite soaring
flying birds. It makes it possible eyeglass wearers can enjoy the overhead will make you a
to scan a sky, an ocean, or an same wide field enjoyed by non- convert.
open marsh quickly. It’s also eyeglass wearers.
easier to locate birds at close Other Important Considerations
quarters in a maze of NOTE: Just because a pair of Whether you are a World
branches. binoculars comes with rubber Series of Birding combatant, a
eyecups does not mean they rock climbing hawk watcher, or
Birding binoculars should offer good or even adequate eye a casual backyard birder who is
also offer good depth of field – relief for eyeglass wearers. The meticulously careful with
a sharp, adjustment-free test is in the length of the equipment – accidents do
image from near to far. A actual eye relief. happen. All birding binoculars
generous depth of field assists should be able to shrug off the
when trying to locate a close- Weather Resistance/ occasional bump and ding.
at-hand bird in a maze of Water Proof
branches. A generous depth of Birding is an activity Superior binoculars are
field mitigates the need to conducted outside, and from impervious to airline baggage
make focus adjustments every the moment a birder takes his handlers, children, and
time a bird moves a little or her binoculars outside, the tumbles onto pavement
closer or a little farther away. outside is trying to get inside precipitated by a combination
those binoculars. of motion, gravity, and a fall
Both field of view and depth to the roadway after being
of field are closely related to In general “Internal Focusing" left on the roof of a car.
magnification. In general, binoculars are better sealed
binoculars with lower against dust, pollen, and Well constructed, well sealed,
magnifications offer greater moisture than “external armored binoculars offer
depth of field, and a wider field focusing" binoculars. To tell another advantage. They need
of view than binoculars with the difference, move the focus no special care – they don’t
higher magnification. wheel and see whether or not even need to be returned to a
the ocular bridge moves. case after use! Hang them up
Eye Relief on the hook by the back door.
Very closely related to field of A very few superior binoculars Put them under the front seat
view, eye relief refers to the are waterproof (not “water of the car. They are there when
distance between the ocular resistant," not “weather you need them. Ready at a
lens and the human eye. This resistant," not “splash proof"). moment’s notice without having
distance is measured in They are waterproof – able to to run to the closet...and grab
millimeters. withstand complete immersion the box from it’s place on the
and remain dry inside. This is a top shelf (out of the reach of
Eye relief is a very difficult (and expensive boast) the kids)...and open the
important consideration for and binoculars that really are case...and remove the
birders who use eyeglasses in waterproof/submersible will binoculars...and extract the
the field and who do not certainly tout this. plastic plugs that protect the
remove their eyeglasses when lenses...and run back to the
fitting binoculars to their You need not bird regularly in kitchen window...to study the
eyes. pouring rain to appreciate the vibrating branch where the bird
benefits of well built, well sealed (that just left) had been
Because the eyes of eyeglass optics. perched.
wearers are already set 10-15
mm behind a glass barrier, they The day you jump from your Lens protection is important,
demand a very “high" eye point air conditioned car into a so most manufacturers of
– a binocular that offers a steamy Florida afternoon and quality birding binoculars
minimum of 15 mm of eye relief. train your now completely include custom fitted rain
© WindStar Wildlife Institute Page 6 A Plant's Home

7. guards with their optics equipment warranty. Quality The Bottom Line
package. Rain guards keep optics come with a warranty Birding is an activity that
things like rain drops, salt that covers materials and offers challenge, excitement,
spray, sandwich drippings, and workmanship. and a lifetime of pleasure. The
hot breath from obscuring better your optics, the less
optics in the field. They also Again, a very few superior frustration you will know and
keep dust off lenses when the optics offer lifetime warranties more pleasure you will get out
binoculars are not in use. Some to the original owner – a of birding.
binoculars also come with special bonus for those who
protective cups for the purchase optics designed and When buying binoculars
objective lens. built to last a lifetime. (and spotting scopes), the
rule of thumb is simple. Buy
Binoculars should come with Spotting Scopes the best binoculars you can
durable, supple, and adjustable In time, after the birds of possibly afford and buy them
neck straps. Leather straps are woodland and field have been as soon as you can afford
chic, but crack and rot under mastered and savored, many them.
normal field use. birders feel compelled to reach
for the horizon. They turn their If you can’t immediately
Plastic straps loose their identification skills upon afford the quality binoculars
suppleness in cold weather and migrating hawks, wintering you want, tolerate the ones
will loop when binoculars are you have or borrow a pair from
seabirds, or feeding shorebirds.
raised – invariably falling a friend. Save for the optics
directly between the ocular lens you really want.
This kind of birding involves
and your eye. careful study over great
If you settle for less, you will
distances for extended only regret your half-step
Most quality binoculars now periods, and in this arena, a
come with straps made of purchase until the day you
spotting scope is ideal.
braided nylon. Wider straps replace them with the
help distribute weight evenly, binoculars or spotting scope
Spotting scopes rest upon a that you really wanted all
saving wear and tear on a tripod, a shoulder stock, or
birder’s neck. along.
specially designed window
mount. Thus stabilized, they Good Birding!
Speaking of wear and tear, make higher magnification
perfection is an ideal that possible, bringing birds on the
optics manufacturers strive for. horizon within reach. Popular
Filling the gap between powers include 20x, 30x, 40x
technical precision and ideal and 60x. WindStar Wildlife Institute is a
perfection is the manufacturers national, non-profit, conservation
organization whose mission is to
Zoom eyepieces are popular help individuals and families
and do not, as a rule, suffer establish or improve the wildlife
the short-comings inherent in habitat on their properties.
About the Author... zoom binoculars. In fact, a few
Pete Dunne, of the New Jersey For more information or for the
spotting scopes with zoom name of a Master Wildlife
Audubon Society, is one of eyepieces offer exceptional
birdings better known figures and Habitat Naturalist in your area,
authorities on the optical needs
optical performance. please contact:
of bird watchers. He is author of
The Feather Quest, Tales of a Low Like binoculars, spotting WindStar Wildlife Institute
Rent Birder, and Hawks in Flight. scopes come in a range of
His regular columns appear in quality and price and also, like E-mail: wildlife@windstar.org
American Birds, Birding, and http://www.windstar.org
Living Bird. He and wife, Linda, live
binoculars, you get what you
near Cape May, New Jersey. pay for.
© WindStar Wildlife Institute Page 7 A Plant's Home