There are many things to consider when deciding which pair of binoculars are best for you. One pair can be great for one person and vastly different for another. More often than not, it comes down to what you want to use them for. Binocular designs vary and depending on the intended type of viewing, they will be aimed at different types of users.
Do you want birdwatching binoculars or are you wanting a lightweight, compact pair to take on a family holiday? Are they just for you or will you be sharing them around? There are pros and cons to almost any pair of binoculars, and we hope that this comprehensive guide will help you with that all-important decision.
There are many, many, many different types of binoculars but first things first - you have to decide what you’re using them for. For birdwatching, you need to decide whether you need reach or the ability to scan and pan along the skies. Fortunately, we offer both options. The higher magnification binos allow you to pick out the fine details of your subjects. The lower magnification, lighter etc. binoculars allow you to acquire your subject and track them through the sky.
Swarovski NL Pure 8x42 Binoculars
Hurry, limited stock!
Swarovski's NL Pure Binoculars are designed to provide the best possible image for long-distance viewing. Swarovski has developed these binoculars so that they can offer one of the widest fields of view on the market. With the use of field flattener lenses, you'll experience edge-to-edge sharpness, incredible image definition and true-to-life images. Furthermore, specialised lens coatings have been added to ensure the maximum colour fidelity possible with accurate colour rendering with high light transmission. A new focusing mechanism has been incorporated into the build which not only makes for much smoother focusing but also has been redesigned to make for a more compact and ergonomic pair of binoculars, perfect for all-day-use. The NL Pure range truly highlights Swarovski's mastery of professional optics.
Pro: Offers an exceptionally wide field of view
Pro: Premium optics and craftsmanship provide unparalleled quality
Con: A very expensive pair of binoculars (but worth every penny)
Con: Great for scanning large areas but not built for observing fine details
Pro: Nitrogen Purged meaning they’re waterproof and fog-proof
Pro: Affordable and comes with Hawke’s lifetime warranty!
Con: Not as ergonomic and tactile as other pairs
Opticron Natura BGA ED 8x42 Binoculars
Featuring wide field optics, ED glass objectives for brighter, sharper images, and a micro hinge body for even better grip, the Opticron Natura BGA ED delivers benchmark quality, optical performance and ergonomics for its price point. The optical system has high-quality phase-corrected prism units with Oasis prism coating, to deliver +99% light transmission over a broader spectrum.
Pro: Compact and lightweight with a textured rubber armour
Pro: Long eye relief eyepieces giving the full field of view for glasses wearers
Con: Accessories are limited and some may find the included strap not robust enough
It’s dark at night and because of that, when looking for suitable astronomy binoculars, you should look for a pair with large objective lenses. This will let the most amount of light in to help you view the stars! A larger objective lens will make the overall size and weight larger but for this, you can get accessories to mount them to a tripod for a steady, shake-free shot.
Pro: Shockproof design with a robust all-metal body construction
Pro: BAK-4 prisms fully broadband multi-coated optics offer exceptional image quality
Con: They’re heavy and generally will require a tripod or stand
Celestron SkyMaster 20x80 Binoculars
Celestron's SkyMaster series of large aperture binoculars are phenomenal value for high performance binoculars, and ideal for astronomical or terrestrial use, especially over long distances. Each SkyMaster model features high quality BAK-4 prisms and multi-coated optics for enhanced contrast. Celestron has designed and engineered the larger SkyMaster models to meet the special demands of extended astronomical viewing sessions, large objective lenses, high magnification, in a reasonably lightweight configuration.
Pro: Very affordable and ideal for those starting out with star gazing
Pro: 80mm objective lens offers maximum image brightness in low-light
Con: While perfect for beginners, its image quality may not be suitable for more seasoned users
Pentax Jupiter 16x50 Binoculars
Observe bright and high-fidelity images with the Pentax Jupiter 16x50 Binoculars. Equipped with 50 mm objective lenses, these binoculars are perfect for scouting distant subjects and rare moments of action. Plus, a protective rubberised armoury safeguards these binoculars against accidental impacts while providing a comfortable grip.
Pro: Affordable and versatile - along with astronomy, they’re ideal for safaris, hiking, trips and more
Pro: Surprisingly lightweight meaning you can hold the binos for longer without fatigue
Con: This pair offers an impressively far optical range, but as a result, the image quality can suffer in certain lighting situations
If you’re looking for binoculars for marine observation, there are several factors to be considered. An absolute must is a pair that have gas-filled tubes - this will ensure that the lenses do not fog up and will be waterproof! You should also be on the lookout for corrosion/temperature resistant polycarbonate - it’s lightweight, durable, and will withstand saltwater environments.
Fujinon 7x50 WP-XL Mariner Binoculars
The Fujinon 7x50 WP-XL Mariner Binoculars are an explorer’s choice. With built-in Porro prism, this pair of binoculars ensure better image quality and a wide field of view. The Fujinon binoculars have a 7.5° angle of view, making them perfect to be used by marine professionals and enthusiasts. Their 56-72 mm range of interpupillary distance makes sure that there is no dark halo around the image when the user is looking through the binoculars. An individual focus mechanism and dioptre adjustment are included in the Mariner binoculars to re-adjust the focus and make them suitable for users with eyesight differences. These binoculars with an 18 mm eye relief are designed to keep well care of the users with eyewear glasses. Apart from the safety of the users, the Fujinon binoculars take care of the lenses with the tethered push-on objective lens caps. Also, users can keep the binoculars clean with the cleaning cloth that comes along.
Pro: Water and fog-proof built, and its 7x mag. is ideal for marine observation
Pro: Tethered objective lens caps keep the lenses protected from dust, dirt, scratches, and breaks
Con: They will float on water if the neckstrap is attached properly - but without the strap, they’ll sink!
Bushnell Marine 7x50 Bearing & Ranging Binoculars
Specifically designed for sailors and marine experts, the Bushnell Marine 7 x 50 Bearing and Ranging Binoculars is an ideal choice for observing distant islands, marine life, water bodies, etc. Equipped with 7x magnification power, the ultra-compact binoculars deliver clear and high-resolution visuals while observing distant subjects. Additionally, the binoculars have innovative BaK Porro prisms that gather maximum light for delivering brighter images, even when the light is not adequate. With sealed O-ring and nitrogen filled tubes, the smart binoculars effectively eliminate fog or moisture formation and feature high resistance against saltwater corrosion. Incorporating an internal rangefinder, the intelligently designed binoculars allow calculating the distance between a user and the target. While an illuminated compass helps in measuring the height of distant objects. And with the rubber armouring on the exterior, the binoculars remain protected against shocks and bumps.
Pro: Its Porro prism design is built with premium optics and provides accurate depth perception - ideal for marine use
Pro: Nitrogen-filled tubes prevent fog or moisture formation on the lenses that would damage the optics
Con: The batteries installation can be tricky (but it’ll be worth it)
Nikon Action EX 7x50 Binoculars
Nikon Action EX 7x50 Binoculars. The newest ATB offering from Nikon is modeled from the best selling Action series roof prism binocular. Like all ATB's, the Action EX is nitrogen filled and o-ring sealed for years of waterproof, fogproof and shockproof performance. A truly extreme and rugged binocular, the Action EX is built on an all-metal chassis with all optical components installed in a lightweight polycarbonate shell. The Eco-Glass lens system provides bright and tremendously clear images, while the streamlined body is rubber coated for a non-slip grip wet or dry.
Pro: This pair will excel for marine use but can easily be used for most purposes
Pro: An ergonomic design that’s also waterproof, fog proof and shockproof
Con: Do not perform as well in low light as other binoculars, but it’s a small trade-off considering the price and overall performance
More often than not, if you’re on a safari, you’ll be far away from your subjects (elephants, zebra, and more scarily - lions). Because of this, you’ll need a high magnification with a large objective lens to bring those subjects closer to you but also to produce a bright and highly detailed image. But if there’s not enough space in your bag, a compact pair of roof prism binos could be useful to help you scan the skies or identify landmarks.
Swarovski NL Pure 8x32 Binoculars - Green
Swarovski's NL Pure Binoculars are designed to provide the best possible image for long-distance viewing. Swarovski has developed these binoculars so that they can offer one of the widest fields of view on the market. With the use of field flattener lenses, you'll experience edge-to-edge sharpness, incredible image definition and true-to-life images. Furthermore, specialised lens coatings have been added to ensure the maximum colour fidelity possible with accurate colour rendering with high light transmission. To further enhance smooth and hassle-free operation, an upgraded focusing mechanism has been implemented into the build. This allows for a more compact, well-balanced, and lightweight form-factor - ideal for every day, all-day usage. You also have the choice between Green and Burnt Orange colour variations to suit your individual style. The NL Pure range truly highlights Swarovski's mastery of professional optics.
Pro: Exceptional image quality and overall performance
Pro: This pair has an extended field of view that makes a substantial difference when viewing from a distance
Con: Expensive compared to similarly ranged binoculars, but when on a safari, this pair will offer the best optical clarity
Leica Trinovid 10x32 HD Binoculars
The Leica Trinovid 10x32 HDs are a rugged pair of binoculars that balance high-end optical performance with impressive portability. They feature P40 phase-correction prism coatings to enhance light transmission, the ever-reliable HighLux system to limit internal light diffraction, and Leica's effective HDC coating to ensure high-contrast clarity and colour fidelity throughout. You are given a truly immersive observational experience when you raise these binoculars to your eyes, with a clear, crisp, and wide 61° apparent angle of view. They also cater well to both those with or without eyewear, with twist-up four-position click-stop rubber eyecups, 16mm eye relief, and ±4 right-eye dioptric correction. For subjects that stand, sit, or fly a little closer to the lens - these Trinovid's are equipped with an immensely short 1m minimum focal distance. This is great for observing small birds, butterflies, bugs, and other insects.
Pro: Exceptional Leica-standard image quality, colour accuracy and high-contrast clarity
Pro: Nitrogen-filled and O-ring sealed; withstanding submersion in up to 4m of water and resistant to internal fogging
Con: Another expensive pair but a worthy and reliable investment that will never fail
Opticron Discovery WP PC 8x32 Roof Prism Binoculars
Save £20, RRP £169
The Opticron Discovery WP PC 8x32 Binoculars are ultra-compact and fully waterproof. With a host of features including 7.5° WA eyepieces, fully coated optics with PC phase corrected prisms, long eyerelief for spectacle wearers with twist type eyecups and excellent close focus ability, the Opticron Discovery WP PC 8x32 Binoculars offer the value conscious customer a stylish user friendly field glass.
Pro: Affordable and perfect for those who are new to binoculars and who want a decent pair to get started
Pro: Long eye relief for spectacle wearers with twist-type eyecups and excellent close focus ability
Con: While an excellent pair for beginners, the optical quality may not meet the demands of seasoned users
The days of night vision binoculars being exclusively a spy’s tool are gone. Nowadays we have various options available to us that allow us to make nighttime observations. We can enjoy watching wildlife at night - seeing what they get up when the sun goes down and light from our lamps go out. Not only this, the once costly and bulky night vision binoculars of the past are now, compact, lightweight and offer a much higher quality image.
Bushnell Equinox Z2 4.5x40 Night Vision Monocular
The Bushnell® Equinox Z2 night vision monocular enables you to see targets more than 750 ft away day or night with a power built-in IR illuminator. Stream live video to you mobile device and control zoom, video recording, image capture, and IR brightness directly from your mobile device
Pro: It can capture high-quality 1080p video during both day and night
Pro: Its built-in IR illuminator allows for viewing long-range targets day or night
Con: The illuminator has only two brightness levels and the battery life isn’t as good as some other models
Celestron NV-2 Night Vision Scope
Free Tripod worth £69.99
The Celestron NV-2 Night Vision Scope supports dusk and night-vision viewing and offers photo and video recording functions. It is a one-hand scope ideal for wildlife observation or security surveillance thanks to its long-distance viewing capability of up to 200 meters away. Paired with its robust and waterproof construction this night vision scope will do a stellar job in the toughest conditions. To top things off, your observations can be recorded on the included 8GB memory microSD card and displayed on a larger monitor with the accompanying audio/video cable.
Pro: Two working modes including Infrared Beam and Low Illumination CCD
Pro: Delivers 4.5x optical magnification along with a 5.0x digital zoom
Con: The eye relief is not long and therefore is not suitable for glasses wearers
Bresser Digital Night Vision 3x20 Binoculars
Expand your horizon with the Digital Night Vision 3x20 Binoculars. With a 4:3 digital display, users benefit from a comfortable viewing experience that brings their subjects closer using 3x magnification. This device also boasts 6 hours of power with the included AA batteries, integrated infrared lighting for use in the dark and a 20mm lens diameter with an adjustment wheel for optimal focus.
Pro: It has a large 4:3 display that is comfortable for longer periods of use
Pro: Impressive image quality, even in pitch black, considering the affordable price point
Con: The battery life isn’t amazing but to be expected. It's always a good idea to carry extra
There are many cases where a pair of binoculars can improve your enjoyment of a sporting event. But as you’ll learn throughout this buying guide, there are many different types of binos that suit differing subjects - sports binoculars are no different. However, if you were to try and pin down an-rounder pair, you’d be looking at 8x42, or a 10x25, for something more portable.
Vortex Diamondback HD 10x28 Compact Binoculars
The Vortex Diamondback HD 10x28 Compact Binoculars welcomes the addition of HD glass elements whilst retaining all of the great improvements made in the last update. This includes better optics, dielectric prism coatings and a 10% lighter body. The HD glass brings outstanding resolution; reduced chromatic aberration; stunning colour fidelity; edge-to-edge sharpness, and fantastic light transmission to an already impressive binocular range.
Pro: Premium High-Density extra-low dispersion glass delivers impressive resolution and colour fidelity
Pro: Lightweight, compact and affordable!
Con: While its lightweight, compactness is a plus; it’s at the detriment of a more premium feeling casing
Olympus Sports 10x25 WP II Binoculars - Black
Designed for the sports fan, the Olympus 10x25 WP II waterproof binoculars are a great addition to your kit enabling you to get closer to the action whether you are on the terraces cheering on your team or at trackside following the action. The waterproof design means that these binoculars are equally at home on land or sea and the convenient focusing means you won't miss a thing from the starting gun to the final flag. Whilst these binoculars have been designed with the sports fan in mind they perform equally well in the countryside when viewing nature's athletes.
Pro: The ideal pair for packing away and quickly viewing at a moment's notice
Pro: Waterproof, travel-friendly and should work for all users
Con: They don’t offer a huge field of view but are perfect for sporting events
Nikon Sportstar EX 10x25 Binoculars
Combining superb optical quality and durability, the Nikon Sportstar EX 10x25 Binoculars provide exceptional performance for watching birds, sports, or just for appreciating the great outdoors. They offer a 10x magnification, while the multilayer-coated 25mm objective lenses ensure the viewed image is bright and clear. The turn and slide rubber eyecups with multi-click allow easy positioning of eyes and comfortable viewing even for eyeglass wearers at the proper eyepoint. O-ring seals and nitrogen gas provide added resistance to the effects of changes in climate for added peace of mind.
Pro: Waterproof (up to 2 m for 5 minutes) and fog-free with O-ring seals and nitrogen gas
Pro: Lightweight, compact and will easily fit in any bag
Con: They do not have the best optical quality but are more than adequate for casual viewing
When we think of binoculars, many will conjure a generic image of a person looking for birds with a big pair of binos hanging around their neck. And, whether you are an aspiring “birder”, a wildlife photographer, a sports fanatic or a stargazer - at first, the world of binoculars can be confusing. How do they work? What do the numbers mean? How far can I see with them?
Well, we’ve put this guide together to explain the ins and outs of binoculars - Binoculars 101 - if you will. Have a read to find out all you need to know before making that all-important decision.
What does it all mean?
We know - there’s a lot to cover. There are all sorts of numbers, prisms and coatings that send us into dizzying bemusement. So, let’s start from the start, shall we?
What are binoculars? Binoculars are an optical device that is constructed from an intricate arrangement of lenses and prisms that produce a magnified view of a subject, object or scene. Unlike a telescope or spotting scope, binoculars feature two parallel optical tubes enabling you to look through with both eyes open - maintaining your depth of field and a more lifelike image.
There are two main types of binocular design - Porro Prism binoculars and Roof Prism binoculars. We’ll dive deeper into these later on, but in brief; where they differ is with the layout of the glass prisms within them. It is the prisms that correct the image we see when we look through the binoculars. Without a prism, the image would be upside down and distorted.
Now, another factor that confuses the matter is price. Often there can be enormous price differences for two binoculars that look seemingly identical. But many aspects can affect the price including the prisms used, the quality of the optical elements, lens coatings and other features such as weatherproofing and the chassis material.
So, let’s get into it.
Do you see what I see?
Let’s talk numbers
Binoculars are categorised by a set of numbers e.g. 8x32 or 10x42. The first number indicates the magnification or strength and the second is the objective lens diameter. If your use a pair of 8x32 binoculars, the 8 refers to the magnification power. This means the image you will see will appear 8 times closer than that of a naked eye.
Why wouldn’t you want the strong magnification? It depends on your use. Binoculars with high magnification are often larger and heavier and therefore can be cumbersome and difficult to hold steady if used handheld. Equally, for example, if your goal is to have a wider field of view so you can easily track birds in flight - a large magnification may be more difficult to operate. A higher magnification equals a narrower field of view - more on this to come.
The second figure (32, in this case) refers to the diameter of the objective lens in millimetres (the part you don’t look through - unless you’re a kid and making everything look tiny - try it). The objective lens is where light enters the tubes. The larger the diameter, the more light is let in resulting in a brighter, clearer and sharper image.
So, surely you would always go for the biggest diameter? It makes sense, but there’s a caveat. Like the stronger magnifications - the larger the objective lens, the larger the overall weight and size of your binoculars.
As you can see, there are most certainly several things to consider before deciding what will be the best option for you.
The exit pupil is the size of the focused beam of light that hits the eye and relates to how bright the image you see will be in low-light conditions. The bigger the exit pupil number, the brighter the image - this is something that needs to be addressed if you intend to use the binoculars in low-light situations such as dusk or dawn.
To find the exit pupil of a given pair of binoculars, you simply divide the objective lens diameter by the magnification - so, for our pair of 8x32 binos, we will divide 32 by 8, giving us an exit pupil of 4mm. The iris of the human eye is generally dilated by 2-3mm in sunlight and 6-7mm in twilight conditions. So, for general daytime use, you could choose a pair of 10x42 or 8x42 binoculars with an exit pupil diameter of around 5mm.
The exit pupil diameter should always be larger than the pupil of your eye. If the exit pupil diameter is smaller than the pupil of your eye, you won’t be able to see a full image and will look like you’re looking through a straw.
Eye relief refers to the distance between your pupils and the eyepiece while the entire field of view is visible. If your eyes are too far away, the image will start to vignette and you will not be able to see the entire scene. The shorter the eye relief, the closer your eye needs to be to the binoculars to see the entire image.
This distance differs from brand-to-brand, and bino-to-bino. This poses a problem for those who wear glasses as glasses prevent the binoculars from being brought close to your eye. While adding that extra distance may seem insignificant, it affects image quality and your ability to acquire sharp focus. Fortunately, there are a few workarounds.
Many binoculars have adjustable eyecups that can be twisted in and out to set the ideal distance for individual users. Others are equipped with foldable eyecups that allow you to get closer to the lens. And then, some binoculars feature dioptric adjustments on one of the eyepieces for fine-tuning the focusing system to suit your specific eye prescription.
Field of View
Before buying a pair of binocs, it’s good to know that the design, size and magnification of binoculars affect the image that you will see through them. As we’ve mentioned previously, the higher magnification, the narrower field of view.
When we say the field of view, we’re referring to the width of the area you can see. It’s usually described in two ways - and while the way people describe it does vary, we’ve adopted “angular field of view” and “linear field of view”.
The angular field of view is the actual angle the binoculars provide - this is usually measured in degrees. The linear field of view refers to the width of the area seen when looking through the binoculars - this is shown in feet at a distance of 1,000 yards, or meters at 1,000 metres.
We can use the angular field of view to calculate the linear field of view. Let’s run some numbers…
1° = 52.5 feet at 1,000 yards
We need to multiply the angular field of view by 52.2.
Take our example pair of 8x32 binoculars - this pair has an angular field of 8°. To work out the linear field of view at 1000 yards, we multiply 8 by 52.5 equalling a linear field of view of 420 ft.
When looking through your choices, remember - a larger number for either the angular or linear field of view means you will see a larger area when looking through. Depending on what you’re planning on using the binos for, a larger field of view will be an ideal view for observing things like moving subjects, birds, wildlife or sports events.
Minimum Focus Distance
Perhaps a bit of an odd one on the surface seeing as we buy binoculars to bring far-away objects into close view. Well, for the most part, this is true. However, there are many users such as wildlife observers who also use their binoculars to magnify plants, flowers and insects - or, birdwatchers, who want to be able to pick out the minute details of their subjects. And, as such, knowing the range in which they will be able to achieve sharp focus between the closest focus distance and infinity is essential!
Generally speaking, as the magnification of binoculars goes up, so does the measure of how close binoculars can focus. If you’re someone who wants to be able to focus on those specific details of your subjects, then you should explore binoculars with a large objective lens (as the extra light helps with detail) and magnification at about 8x (anymore, and your minimum focusing distance will be too far).
Most binoculars feature a central focusing system, operated by a main focusing wheel located on the bridge between the two optical tubes. This is the most common style and easiest to operate for any level of user. A feature of this style is a dioptric adjustment dial (like we covered previously) that is often on one or both of the eyepieces that allow you to fine-tune the focus to suit prescription glasses etc. (this dial can be integrated into the central focusing mechanism, and the level of diopter correction differs from brand to brand.)
You may come across binoculars with other focusing systems such as individual focus models that allow you to separately adjust focus for each eyepiece. This is ideal for precision focusing, especially if you know one eye is more short or farsighted than the other. This is a system for solo users - you don’t want your setup to be changed if you’re sharing your binoculars.
Another type you might come across is binoculars which are often called “auto-focus binoculars” or “self-focusing binoculars”. This is confusing and misleading because they don’t focus automatically and they should be referred to as focus-free binoculars. They rely on the flexibility of your eyes to keep the image clear and in focus. Now, a few things to note.
Focus-free binoculars don’t have any focusing mechanisms and therefore, fewer moving parts. This makes them often more lightweight, compact, robust and cheaper. They are also much easier to make fully dust/waterproof and because of all of these reasons, they’re well suited to harsh conditions, observing objects while moving (e.g. hiking) and are well-suited to suddenly appearing subjects (e.g. birdwatching). Sounds good, right?
Well, it should be noted that binoculars like this put a lot of stress on your eyes and can cause discomfort - generally not a problem for children or young adults. But as we age, our eye’s ability to focus slows and because of this, this type of binocular can cause eye strain. Also, binoculars with a fixed focus tend to only focus from 10-12 metres onwards meaning they’re not ideal for everyone - they’re aimed at those who want to view wide open areas.
It’s what’s inside that counts
Porro or Roof
Okay, we’re back to prisms again - as promised. As mentioned before, there are two main types of binocular design - Porro Prism binoculars and Roof Prism binoculars.
Porro prism binoculars feature an offset internal prism to magnify an image. Because of the wider distance between the two object lenses, you’ll be able to see more true-to-life, 3D images compared to the roof prism design. They’re also simple to build and offer decent optical quality at a low, cost-effective price. But as always, there’s a tradeoff. Porro prism binoculars are larger and heavier than roof prism designs, so are not ideal for travelling or any situation really where you want to be able to tuck your binoculars in your bag.
In roof prism binoculars, the optical elements are aligned with one another which in turn, allows for much more compact, lightweight and portable designs. Naturally, roof prism binoculars have become the preferred option because of their portability without sacrificing image quality. And, thanks to modern optical engineering, most roof prisms offer higher image quality and overall performance.
But of course, it’s not as clear-cut as it may seem. As mentioned, Porro prisms are generally cheaper and more simple to build. You may find that you can purchase a pair of porro prism binoculars with better image quality and/or a large objective lens for the same price as a roof prism pair with lesser optical quality.
The quality of the glass used to produce lenses and prisms is the most important aspect of a decent pair of binoculars (or camera lenses, for that matter). Inferior craftsmanship or materials with imperfections can have a significant effect on the quality of the image you see. Scenes may have strange colour casts, be distorted or you simply will not be able to get your image in focus!
Many binoculars will boast specialised glass such as low dispersion or extra-low dispersion glass that is specifically designed to suppress or eliminate optical distortion or aberrations. The result of this is cleaner, sharper, high-contrast images with true-to-life colour rendition. All of which explains the drastic differences in price tags.
The materials that prisms are made out of hugely impacts the image quality of binoculars. There are three main types of prism material: BaK-4, BK-7 and SK15.
BaK-4 (Baritleichkron, a type of Barium Crown glass) is considered one of the best materials for building prisms due to its high refractive index and lower critical angle resulting in high light transmission and low internal reflections.
BK-7 glass is the most common material used and is generally found in lower-priced binoculars. This type offers excellent light transmission and generally has very few internal imperfections, but does not match the quality of the BaK-4
SK15 glass sits in the middle of BK-4 and BK-7. It features a higher refractive index than both, but the light dispersed or separated when passing through a lens is somewhere in between.
Coatings are specially designed chemical-based films that are applied to both lenses and prisms to reduce glare and reflections, increase light transmission and contrast, make colours more vivid and generally improve image quality. You’ll come across terms like coated, fully-coated, multi-coating and fully multi-coated and phase-coasted which refer to the type of coating used and where the coating is located. Let’s take a look at each type of lens coating:
Coated lenses have at least one thin anti-reflective coating on one or more lens surfaces.
Fully coated lenses have a least one thin anti-reflective coating on both sides of the objective lens and both sides of the lens system.
Multi-coated lenses have as the name suggests, multiple layers of coatings on one or more of the lens surfaces.
Fully multi-coated lenses will have multiple coatings on all lens surfaces. This level of coating is usually associated with high-end optics and is a sign of professional craftsmanship.
Phase coating affects roof prism binoculars. Because of the linear design, light passing through the tube gets reflected on itself for a short distance. When this happens, some light waves that lined up the tube go out of phase causing interference that reduces brightness and sharpness.
Prism Coatings are used in conjunction with lens coating, further increasing light reflection and improving image brightness/contrast. There are many types, of which most will use standard reflective coatings, but some high-end binoculars have specialised dielectric coatings applied to the prisms, that allow more or less 100% of light through the prism and therefore, it produces a brighter, higher contrast image.
Another type of coating is used to correct the effect of phase - a problem only affected by roof prisms. The reason for this is due to the way light moves through the tubes. As light passes through the objective lens, it is split into two separate and independently travelling beams of light. When the two beams are recombined in the eyepiece lens they are slightly out of phase with each other (because one will hit the eyepiece milliseconds before the other) causing poor colour imbalance and colour rendition. The use of a phase coating slows the faster beam to the same speed as the other - bringing them back into phase - so they hit the eyepiece at the same time. This vastly improves colour, contrast and clarity.
Lens and prism coatings are generally a good thing as long as they actually do something. There are many cheaper coatings that, while they may make binoculars look “cool” (e.g. a “cool” colour tint to the objective lens), may not provide any optical benefit.
There are several materials that the frame of a pair of binoculars can be made from. Most popular and most commonly used is aluminium alloy. It’s lightweight, strong, easy to work with and inexpensive. It’s also naturally resistant to corrosion, which is a big plus. However, don’t be drawn in by things like “aircraft-grade” unless a specific grade is mentioned e.g. 6061-T6. Any material used in an aircraft is “aircraft-grade” - you need to look out for the graded materials that have proven strength and corrosion-resistant properties. Generally, if it says aluminium, it will be strong and lightweight.
Magnesium allows is another material used for its high strength-to-weight ratio - it is also often used for camera bodies for this exact reason. The main benefit of magnesium alloy binoculars over aluminium ones is that they will be lighter and therefore, will cause less fatigue if you’re using your binoculars for long periods. They’re also very strong so will withstand the rigours of outdoor use (and/or children dropping them…)
You’ll also come across polycarbonate chassis. This is a material often used for binoculars that are intended for use in extreme temperatures. Unless metals, a polycarbonate frame with not only remain the same temperature in extreme temperatures, but it will not expand/contract when put through fluctuating temperatures. This will prolong the effective use of the binoculars over metal counterparts as over time, temperature changes can misalign the optical elements inside and therefore, make it more difficult to achieve precise focus.
Weather Resistant, Waterproof, Fog Proof
You’d think if you have one, you’d have them all. But this is not the case and determining what each rating means will dictate where/when you can use the binoculars. We’ve split this up to make things a little clearer.
Binoculars with no weatherproofing or rating should not be used in the rain, at sea or anywhere where there is moisture. Moisture can find its way into the tubes and when you look through, the heat from your face will cause the moisture to condense and “fog” up the lens, limiting your view and ability to focus - it will also eventually cause rust and corrosion.
Weather-resistant binoculars, generally, will use a form of seal to ensure moisture from humidity or mist from getting inside the optical tubes e.g. an O-ring. This is a simple but effective measure that will allow you to use your binoculars in humid, muggy, sticky or midst conditions without causing damage. However, this does not mean they’re fog-proof.
Like the weather-resistant rating, waterproof binoculars have a seal that prevents moisture from getting into the optical tubes. However, it all depends on the grade of the seal, the materials and the craftsmanship. Effective waterproofing allows you to submerge your binoculars for a varying amount of time - some are for limited depths for a limited time, while others are built to military standards and therefore can be submerged for much deeper/longer. However, like the weather-resistant rating, having waterproof seals do not necessarily mean they’re fog proof.
So, what is “fogging”? Fogging occurs when there is moisture present in the air contained within the binoculars. Just as we see a person wearing glasses open an oven door and get all steamed up, if you take your binoculars from one extreme temperature to another, the air will condensate and cause the lenses to fog.
Fortunately, we live in a world of geniuses who created fog-proof binoculars that use dry, inert gases to prevent fogging. Gases such as nitrogen or argon (or a combination) are pumped into the tubes under pressure, keeping the seals firmly in place and ensuring no moisture can get in. There’s a conversation as to which gas is best e.g. larger molecules are less likely to leak and therefore, prolong water/fog proofing over time, but this isn’t something that needs to be considered from a consumer point of view. The takeaway is, that gas-filled binoculars (whichever inert gas it is) offer effective fog-proofing that is ideal for hiking in high-altitude climates, near open bodies of water, or bird spotting in humid conditions.
Up until now, we’ve been discussing standard binoculars, but there are several speciality binoculars that we’d like to cover. Now, there is some cross-over with the features but we’ll separate it to make things more simple:
Generally, the more powerful binoculars are, the larger and heavier they’ll be, making them more difficult to hold steady and view a sharp, shake-free image. Like a DSLR or mirrorless camera with IBIS (In-Body Image-Stabilisation), image-stabilised binoculars can compensate for user movement, correcting the scene to make a clearer, shake-free image. There are three types of stabilisation used gyroscopic, electronic, and mechanical.
Gyroscopic stabilisation is achieved with internal gyroscopes that provide a reference that is used to move prisms and stabilise the image.
Electronic stabilisation uses small accelerometers to measure any movement which then sends commands to adjust the prisms to counteract that movement.
Mechanical stabilisation uses an array of small counterweights that move to balance the image, counteracting any motion caused by hand-shakes etc.
Are they for everyone? No. But they are often used by those who work at sea where if you were to use standard binoculars, the swaying and movement of the boat can cause a lot of disorientation or nausea. They’re also popular with aviators and search-and-rescue professionals to achieve a shake-free image.
There are also some drawbacks - binoculars with this technology are often heavier and more costly than standard binos, but more importantly, they are powered and therefore require periodic battery changes.
As the name suggests, these binoculars zoom! They offer a variable magnification that allows you to explore a scene or a subject in further detail. Take a pair of zoom binoculars with an 8-24×25 range - you have an 8x magnification at the low end and 24x magnification at the high end. This is usually accessible by a thumb lever or conveniently place while that is in reach without the need to change your grip or take your eyes any from the optics.
It’s good to know that optical paths and the physics of prisms are optimised for a single power. While the ability to zoom in is great for surveying a scene and provides you with greater versatility - the more you zoom in and more away from the optimal magnification, there will be a level of degradation in image brightness, and sharpness and therefore, image quality. Depending on your use, this may or may not be an issue.
We briefly mentioned these earlier on in this buying guide, but we’ll go into more detail here. Marine binoculars are definitely a speciality, featuring many aspects covered through this piece. They’re often made from that corrosion/temperature resistant polycarbonate mentioned earlier that is lightweight, durable, able to handle saltwater environments, and has the added bonus of generally being buoyant - ideal should you accidentally drop them overboard.
They’re also usually gas-filled for fog/water-proofing, which is vital in this environment. Many marine binoculars are also equipped with integrated digital and analogue compasses as well as featuring image-stabilisation and/or integrated rangefinders. They vary in price but generally, the more bells and whistles, the more expensive they will be.
Night Vision Binoculars
Specialised and often quite expensive, night vision binoculars usually have a low magnification and are equipped with either a light intensifying function to boost ambient light levels or an in-built infra-red lamp to artificially illuminate a scene. This infra-red illumination is invisible to the naked eye but can be seen via the battery-powered sensor in the night-vision binoculars. Some models feature an SD card slot that allows you to capture stills or record videos of the scenes in front of you. Night vision equipment is available in several different styles from binoculars to monoculars, and depending on your use can be a great addition to your kit bag!
In many cases, binocular accessories serve to replace lost or broken parts. But we’re going to focus on the parts that will simply make using or carrying your binoculars easier.
Neck Straps - There are a huge number of straps out there to choose from. Adjustable, padded, coloured - you name it. There’s something out there for everyone and every occasion!
Harness - In some cases, the provided neck strap is either not enough or simply not suitable for your excursion. For this, you can explore harnesses that allow you to attach your binos to you over your shoulder, on your back or around your waist. There are all sorts out there that will best suit your activity.
Tripod Adapters & Mounts - The larger the binos, the more cumbersome they are. This can make them more difficult to hold and/or hold steady. Often used in bird hides to provide stability and a steady image, you can use a tripod adapter or mount to attach your binoculars to a tripod/surface. This makes those longer observation sessions much easier.
Tethered caps - Forget losing your all-important objective lens caps. Get some tethered caps to loop over the objective lens end. Simply flip them down and you don’t have to worry about losing them.
Rain Guards - These guards replace the caps that come with your binos. They sit over the eyepieces of the binoculars to protect them from precipitation when being worn around the neck.
Cleaning Kits - We have to keep our binoculars clean and clear of debris to ensure the best possible image. For this, there is a plethora of liquid lens solutions, pens, cloths and cleaners.
Digiscoping Adapters - Perhaps you don’t own a camera and a long lens but you want to snap a shot of a bird, animal or scene that you’ve seen through your binoculars. Look no further than a digiscoping adapter. This adapter allows you to mount your smartphone camera to your binoculars and take pictures of the magnified view!
Have you considered…
We’ve been covering binoculars of all shapes and sizing but perhaps a different type of optic would better suit your needs?
Rangefinders are battery-operated devices often used in sports such as golf or archery to measure the distance between the view and the subject. While you could use it to observe a scene, it is not the ideal viewer apparatus.
A monocular is essentially half a pair of binoculars and serves the same purpose - magnifying distance objects or scenes. However, while binoculars are used for observing, often at length, monoculars are most commonly used for scanning a scene and identifying target locations etc. However, they’re significantly lighter and smaller than binoculars and may be ideal for those who want to observe wildlife or subjects but can’t afford the space taken up by binos.
Spotting scopes tend to veer into another area of observation but still offer essentially the same result - a magnified view of a scene, object or subject. They’re generally more cumbersome when compared to other optics and usually require a tripod or mounting system. But it all comes down to your intended use - if you’re creating a permanent viewing station or require the highest level of optical quality, a spotting scope could be the option for you.
We like to think we’ve covered a lot within this buying guide but sometimes you just want the straight facts. Well, here are some of those terms and FAQs that are essential when it comes to binos!
Magnification - This refers to the strength of the binoculars and therefore, how close the object will be. But this should be considered in conjunction with the diameter of the objective lens.
Prisms - Prisms are used to correct the inverted image projected by the objective lens as light passes through.
Porro Prisms - Porro prism binoculars feature an offset internal prism to magnify an image. The light passing through forms a "Z" shape before reaching the eye.
Roof Prisms - A more modern prism design where light passes through in a straight line that allows for more compact binoculars.
Exit Pupil - The exit pupil is the size of the focused beam of light that hits the eye
Eye Relief - This refers to the distance between your pupils and the eyepiece while the entire field of view is visible.
FOV - Field of View refers to the width of the area you can see when the entire image is visible.
Gas-filled - Inert gases such as nitrogen or argon (or a combination) are pumped into the tubes under pressure, keeping the seals firmly in place and ensuring no moisture can get in.
Q: What do the numbers on binoculars mean?
A: The first number indicates the magnification or strength and the second is the objective lens diameter. The second figure refers to the diameter of the objective lens in millimetres
Q: Can I wear glasses with a pair of binoculars?
A: You can wear glasses and use binoculars but you’ll need longer eye relief to allow room for your glasses.
Q: What’s the difference between BAK4 and BK-7 prisms?
A: These two types are made from different materials that offer different optical qualities. BaK4 offers the highest level of optical quality, whereas BK-7 prisms offer a high image quality but do not perform as well in lower light conditions.
Q: What strength of binoculars is best?
A: This is all very much dependent on the subject you wish to observe. A lower magnification pair will be lighter and more portable but will not offer an image as zoomed in as a pair with higher magnification. But for everyday users, a lower magnification will be easier to use and pack away in your bag.
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How did we decide?
Our in-house photography experts, store staff and partners all work collaboratively to pour over these guides. The cameras and equipment recommended in our guides are based on their personal opinion, empirical experience and of course, feedback from our customers.
We way up price, features, quality and the all-important 'je ne sais quoi' to make sure we recommend products that will delight and inspire.
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About the Author
Leo White has been a member of the Wex Photo Video team since 2018, working in a variety of roles ranging from the contact centre to the product setup team. With both a photography BA and MA, Leo has a wealth of knowledge he's ready to share. See more of his writing on Leo's author page.