MAGNIFICATION POWER – For example 10×42
The first number is the magnification power, or how many times the image is enlarged. The two most common magnification powers are 8x (8 times larger) and 10x (10 times larger).
Don’t be fooled into thinking bigger is better. More power is not always better. Although a higher power binocular will increase the size of the object, higher magnification also magnifies the effects of your hand shaking and it can appear that the image is shaking or perhaps a bit blurry.
Stick to a 7x, 8x or 10x power binocular for best results.
Try typing 10x (for example)
The second number indicates the diameter in millimeters of the larger front lens (known as the objective lens). The bigger the objective lens, the more light can enter, and the greater the potential resolution of the image, especially at dusk and dawn. Most popular birder binoculars would be a 42mm.
PORRO PRISM or ROOF PRISM
Porro prism binoculars are what you would consider traditional shaped binoculars. They are wide-bodied with a big lens in front and a smaller one in the back. The shape of the binoculars looks a bit like a ‘dog leg’.
Roof prisms are longer and sleeker in design with the objective and ocular lenses falling in alignment along the same tube.
Both designs have advantages and disadvantages. Porro prism binoculars have fewer internal elements and are easier to manufacture and repair. Roof prisms, are more expensive but also tend to be more rugged with elements firmly anchored within the barrels.
FIELD OF VIEW (FOV)
The field of view is the size of the area you can see through a binocular. It refers to how much you can see left to right and top to bottom. Field of view is measured in feet at a distance of 1,000 yards from where you would be standing. (An example spec on a binocular would be: Field of View: 356 feet @ 1000 yards.)
Select a field of view that offers a minimum of 300 feet at 1,000 yards.
A wider field of view makes it easier to pick up and identify fast flying birds. This makes it possible to scan a sky, an ocean or an open marsh quickly. Generally, lower magnification binoculars offer a wider field of view than binoculars with higher magnification.
EYE RELIEF
Closely related to field of view, eye relief refers to the distance between the ocular lens and your eye. This is the most important consideration for eye glasses wearers, because glasses hold the eyes back from the eyepieces, and you may not get to experience the same wide fields enjoyed by non-eyeglass wearers.
Normal eye relief for binoculars is measured in millimeters and should be from 9 to 13 mm. Even though the eyecups of most binoculars fold down to let eyeglass wearers get closer, in many cases it’s not close enough. If you wear glasses, you need binoculars with a longer eye relief of 14 – 20 mm.
CLOSE FOCUS
The closest distance to the observed object that a binocular can focus down to.
EXIT PUPIL
Hold a binocular up to the light and look in the eyepiece. Exit pupils are the small, bright circles. The exit pupil is the column of light that comes through the binocular to your eye. The larger the exit pupil, the brighter the image.
The exit pupil is calculated by dividing the diameter of the objective lens by the power: (Example 35 divided by 7 = 5). So, a 7x35mm binocular has an Exit Pupil of 5.
SPOTTING SCOPES
Advanced birding involves the careful study of birds over great distances for extended periods of time. For this task, spotting scopes are ideal. Spotting scopes usually rest upon a tripod, making stable, higher magnification possible.
The most popular magnification powers include 20x, 30x, 40x and 60x. Many spotting scopes offer excellent zoom eyepieces and adaption to 35mm cameras as well.
CHECK THE PRICE
Good binoculars simply cost more to manufacture than less expensive ones. Heavier glass, coatings, more precise alignment, better quality control all contribute to a higher cost. Basically, you get what you pay for with binoculars.
WHAT ARE YOU USING THEM FOR?
BIRD WATCHING
A wide range of binoculars may be used for bird watching and nature study. An 8×21 model may be fine for observing a blue jay in your backyard on a bright, sunny day. However, if you are in a shaded area, binoculars with a larger objective lens would allow more light to enhance your view.
Once the basics of binoculars are understood, the decision will be easier. A good pair of binoculars will give you a good field of vision, be able to focus quickly, fit your hands, are still okay when knocked to the ground, be able to withstand some rain or fog, and allow you to see objects both near and far.
Generally, an 8 or 10 times magnification combined with an objective of between 30mm to 42mm is the best combination.
BOATING / YACHTING
Most manufacturers feature a 7×50 model as their marine binocular. The large 50mm objective lenses perform well in low light conditions. If you plan to view at great distances, a 10×50 model might be better. For those viewing only in bright daylight conditions who prefer a more compact model, an 8×21 or 8×25 would work well. Also note, Rubicon (Ruby red) coated objective lenses are helpful in reducing glare in bright sunlight, and/or over the water.
CAMPING / HIKING
The outdoor enthusiast will probably be carrying much of their gear and would therefore want to keep the load as light as possible. See our compact / Travel section for best choices.
ASTRONOMY
With binoculars the Moon is fascinating through all the lunar phases and even Jupiter and the four moons that Galileo saw is quite possible.
Any binoculars will show you a lot more than you can see without them and wherever possible try to steady them with either a standard tripod or just lean against a fence or post.
For those keen to explore the night sky we recommend that you check our telescopes section.
Of particular interest for use in astronomy is the ratio between magnifying power and objective lens diameter. Due to the way binoculars are made, the resulting ratio is the diameter of the final exit pupil on the oculars. For example, a 10×50 binocular produces a 5 mm exit pupil (objective size divided by the magnifying power).
For maximum efficiency, this image should match the diameter of the eye’s pupil, which in dark environments grows to about 7mm.
This ratio is also a measure of the brightness of the image, the larger the exit pupil, the brighter the image reaching the eye. Therefore, 10×50 and 8×40 binoculars have the same brightness, although the latter has a smaller magnification.
An exit pupil larger than the diameter of the user’s eye pupil wastes light.
Binoculars are widely used by amateur astronomers. Their wide field of view is central to their use in comet hunting and general sky observing.
SPECTATOR SPORTS
Race enthusiasts know that good binoculars are an important piece of gear for catching a closer glimpse of the action. A wide angle binocular which offers the advantage of a wider field of view will let you see more of the track and, consequently, more of the action. Focus free binoculars allow you to simply pick up the binoculars and view, without having to make time-consuming focusing adjustments.
A night game is better seen with larger objectives, a day-time event can be viewed with a more compact binocular. If you are in a large stadium watching a football game, (depending on where your seats are), a pair of 7×35 binoculars might be ideal. If you are seated at one end, or in the upper rows of the stadium, 10×50 would be better suited for your needs.
SURVEILLANCE
These binoculars offer many performance options: lightweight, wide angle and zoom among them. Zoom binoculars can capture a panorama of action at low power, then zoom in to pick up all the details at higher powers.
TRAVEL / SIGHTSEEING
The needs of travellers are diverse. As such, the features and benefits of the various binoculars are equally diverse. The recommended binoculars for travel and sightseeing range from compact, lightweight models that go everywhere, to large zoom models that allow for a range of magnifications in one binocular. Whatever your pleasure, we have a binocular to fit your need.
BINOCULAR STYLES
Compact binoculars offer the advantage of being extremely portable and lightweight. With the prisms positioned one over the other utilising the Roof prism design, the objective lenses and the eyepiece centers are lined up creating a compact design with full size power. Some compact binoculars will even fit into jeans and jacket pockets.
Full size binoculars offer superior light gathering capabilities and wide fields of view.
Zoom binoculars allow you to lock onto a subject, then zoom in for a closer view. Zoom binoculars have two power numbers which represent a range of powers. A 10-30×50 binocular for example, brings objects from 10 to 30 times closer.
Focus-Free binoculars offer a “no focus” mechanism which means the binoculars are always in focus. Simply pick them up and look. They’re always in focus ready to catch all the action and are proving to be very popular with people who need to look quickly to catch something such as plane-spotters, travellers and yachtsmen.
Please note however that they are designed for people with normal or corrected to normal vision. The distance from which they are in focus varies from person to person.
Wide angle binoculars offer greater field of view without sacrificing power. By altering the design and shape of the binocular’s lenses an increased field of view can be obtained without sacrificing power.
Wide angle binoculars are ideal for sports events to capture quick movements, or for races when the action is spread over a broad area or for travel where a panoramic view is desired.
Rubber armoured binoculars provides multiple benefits. It helps protect the binocular from the bumps and scratches by absorbing shocks that occur with general use. It provides a comfortable, ergonomic, non-slip gripping surface for making them easier to hold on to, particularly in the elements, while insulating your hands against extreme temperature. It’s easy to wipe clean after a tough day in the field. And it suppresses noise if the binocular bumps aluminum or other non-rubber surfaces, which might otherwise spook wildlife
Waterproof binoculars have been hermetically sealed and nitrogen charged to remain dry when submersed in water. They have been tested underwater and proven to be completely waterproof.
Some binoculars are O-ring sealed and nitrogen-purged for total waterproof and fog proof protection. These models can withstand complete immersion in water and stay dry inside. The interior optical surfaces won’t fog due to rapid temperature change or humidity.
To accommodate boaters and fishermen, models also include a built-in compass and a range-finding reticle.
To complement our waterproof binoculars we suggest our floating binocular straps, which offer extra comfort as well as extra security in case of accidental spills overboard.
Tripod Adapter and Bracket
When a binocular reaches higher powers (generally over 12x) you will need some assistance to hold it steady enough for comfortable viewing. While leaning against a fence or tree will often suffice, a much better solution is to use a tripod. Most higher magnification models will include a tripod adapter fitting at the base of the hinge (covered by a screw-in cap).
A monocular is a modified refracting telescope used to magnify the images of distant objects by passing light through a series of lenses and prisms ; the use of prisms results in a lightweight telescope. Volume and weight are less than half those of binoculars, making it easy to carry along.
It’s not possible to label individual binoculars as the best for any particular use or situation due to variables such as usage conditions, individual preference, how and where the instrument will be used, and the range of different viewing situations the instrument will be used for. Only you can determine what will be the best, most versatile and satisfactory optical instrument for you, and you shouldn’t be discouraged from any choice you make, because you know your own needs and interests. We encourage you to look through the information provided at this site on the different models, then ask us for a demonstration. Whichever product you choose, rest assured that you’ll receive excellent value for your investment.
The brilliance and sharpness of the image you see through a particular binocular or spotting scope is determined by a number of different factors. Magnification, optical coatings, and lens diameter are just a few of the factors influencing how a binocular performs.
However, the single most important criterion in performance will always be the quality of the optics. Optical excellence is delivered through careful consideration of quality in the glass and lens coatings used, precision manufacturing processes, and uncompromising quality control.
SPOTTING SCOPES
A spotting scope is a portable telescope , optimised for the observation of terrestrial objects. The magnification of a spotting scope is typically in the order of 20x to 60x. Other common features include:
somewhat “rugged” or rubber-armoured design
convenient mounting for attaching to a tripod
ergonomically designed and located knob for focus control
tethered elastomeric lens cap
a range of eyepieces to give different magnifications, or a variable “zoom” eyepiece to give a range of magnifications (e.g. 20-60x)
The light gathering power of a spotting scope is determined by the width of the objective lens , typically between 55 and 80mm. All else being equal, the larger the objective, the more heavy and expensive the telescope.
There are three types of scope: “straight-through” (the eyepiece is one the same axis as the body of the scope), “angled” (the eyepiece is at an angle of about 45 degrees to the body of the scope), and rarely, a more complex, shoulder-mounted design. Straight-through scopes are easier to use from, say, inside a car, while angled scopes are more comfortable for tall people and more easily shared by people of different heights.
The choice of the eyepiece lens determines the overall magnification. The best magnification is decided by a number of factors. Magnifications of less than 20x are unusual, as (much cheaper and lighter) binoculars or monoculars can provide this. Magnifications of more than 60x lead to poorer brightness and, even on a tripod, shake can be a problem. The field of view is also limited.
Usually for birding , 20x or 30x is favoured. This gives a good field of view and a bright image.
