Everything you need to know about binoculars
Like tripods, binoculars can be a little confusing to shop for - at first glance, they all look a bit similar, and all seem to have the same general purpose. But while they do all serve to magnify a scene, binoculars can in fact vary greatly in size, type and features. You have to know what to look for, if you want to know how to buy good binoculars.
From high-powered binoculars that can see right up to the stars, to small foldable binoculars that are perfect for everyday use, we explain the basics and what to look for when you're buying a pair of your own.
Table of contents:
- How do binoculars work?
- What are the different types of binoculars?
- What do the numbers on binoculars mean?
- The binocular specs you need to know about
- Binocular uses and recommendations
How do binoculars work?
Every pair of binoculars is made up of two lenses: the objective lens (which is closest to the object), and the eyepiece lens (which is near the human eye). The objective lens combines convex and concave lens to capture an image, and the image is then magnified by the eyepiece lens - so that you can clearly see a subject or landscape that's far away.
What are the different types of binoculars?
While all binoculars have the same basic lenses, they're constructed differently. The majority of binoculars fall into two categories: porro prism and roof.
Porro prism binoculars are the most common type by far. They're designed so that the optical path is bent like the letter Z, which means the image formed by the objective lens is reflected by two prisms. This gives the binoculars their distinctive shape, where the objective lenses are wider than the eyepiece lenses.
While the image they offer is clear and detailed, the binoculars themselves are typically large and heavy. Porro prism binoculars are easy to manufacture - and that's why they're so popular.
With roof binoculars, the objective and eyepiece lens are aligned in a straight line. Since the area where the two prism blocks meet must reflect light at some points, and let in light at others, this design makes it harder to create a crisp, clear image. However, this design is more ergonomic, and can usually handle higher impact than porro prism binoculars.
Compared to porro prism pairs, roof binoculars are compact and travel-friendly. For these reasons, they're more expensive - but they have a huge and loyal fan base.
At Ted's Cameras, most of the products we sell are porro prism or roof binoculars.
However, we have a range of binoculars that fall under these categories, too:
- Foldable binoculars - If you don't need standard, full-size binoculars, foldable models are compact and lightweight. They can easily fit into a handbag or backpack, and are ideal for concerts, theatre and the opera.
- Wide angle binoculars - We'll delve into this soon, but these binoculars have a wider Field of View (FOV), so they're great for spotting objects across larger areas.
- Zoom binoculars - As the name suggests, zoom binoculars have more choices when it comes to magnification. (If you're a photographer, think of these in a similar way as zoom lenses, while fixed power binoculars are closer to prime lenses).
- Waterproof binoculars - Some models are water-resistant, which means they're protected from water splashes. Waterproof binoculars are fully weather-sealed and can be completely submerged in the water. On that note, shockproof binoculars are perfect to take on bumpy adventures, like safaris or rides on a speedboat.
- Focus-free - These are often called self-focusing or auto-focusing binoculars, but those terms are misleading. Focus-free binoculars don't have a focusing mechanism. Instead, they have a fixed depth of field, and everything within that range will remain in focus.
- High-powered binoculars - Ideal for long-distance terrestrial viewing, high-powered binoculars have a super-high magnification. Many astronomers use them as an alternative to telescopes. If you're interested in exploring the night sky further, our beginner's guide to astrophotography walks you through everything you need to get started.
- Tripod-mounted binoculars - Like cameras with a large zoom range, binoculars with high magnification power will deliver a clearer, steadier image when mounted on a tripod. If you often shake when you're holding binoculars, look for a pair that's compatible with a tripod. If you're unsure which tripod to pair with your binoculars, our guide to the best tripods covers the top options across every budget.
- Night vision binoculars - Put simply, night vision binoculars turn photons into pools of light that are visible to the human eye. Even simpler? They allow you to see your subject in the dark. These binoculars are used for sports and surveillance purposes, as well as other leisure activities.
What do the numbers on binoculars mean?
When you're shopping for binoculars, you'll spot two numbers with an x in between. For example, 20 x 60.
The first number refers to the magnification.
The second number is the size of the objective (front) lens in millimetres.
The larger the objective lens, the brighter the image will be. Binoculars with large objective lens are often heavier and bulkier, but they work well in low light - which means they're great binoculars for stargazing and similar purposes. Binoculars are also a fantastic companion for whale watching — check out our whale watching photography tips to make the most of your next outing.
When it comes to magnification and lens size, there aren't good or bad binoculars. The best pair of binoculars is the one that suits your needs - and we'll talk more about that in a minute.
The binocular specs you need to know about
Binoculars have their own set of specs, and understanding what they mean will make it much easier to pick the right pair for you.
These are the key elements of binoculars:
Magnification - Remember, this is linked to that first number you'll see on every pair of binoculars. The greater the magnification, the larger the binoculars will make subjects appear as you look through them. For example, if your subject is 150 metres away, and your binoculars have a magnification power of 10x, the subject will look the same size as the one that's 15 metres away when you're not using binoculars.
Did you know? Some binoculars are fitted out with digital magnification, and also allow you to take photos and record videos. These are called binocams.
Brightness - As for brightness (the second number), a larger objective lens lets in more light and detail, so you'll see a crisper, clearer image through your binoculars.
Interpupillary distance, dioptre adjustment and eye relief - This is a lot of jargon, so let's break it down:
- Interpupillary distance is the space between your two eyes. To use your binoculars comfortably, you want to make sure they can be adjusted to sit on the bridge of your nose.
- Every pair of binoculars offers a degree of dioptre adjustment. This means you can adjust the lenses according to your eyesight in your left and right eye to get a crisp, sharp image. If you have one eye with better sight than the other, you're not alone!
- Finally, eye relief refers to the distance between the eyepiece lens and the eyepoint (aka the surface you press your eye against). If you wear glasses, look for binoculars with a longer eye relief. That way, you won't be restricted to a smaller field of view.
Field of view (FOV) and range finding - The field of view is the width of the scenery you can see through your binoculars. It's measured in degrees, and the larger the number, the wider the FOV. Binoculars with wide FOVs are good for scanning scenery, and observing quick movements (like a fast-paced sports game, or animals chasing each on safari). Planning a trip? Our guide to photographing an African safari has practical advice on gear and preparation. Many binoculars are also equipped with a rangefinder. This superimposes a scale on your image, so that you can estimate your distance to the object. The feature comes in handy if you're hunting or golfing.
Optical quality and lens types - The optical quality is all about clarity. High-quality lenses can optimise the available light, and eliminate glare - leaving you with a superior image. They can also perform well in all lighting conditions, and help to colour-correct and offset imperfections. As you may have guessed, binoculars with extremely high optical quality are often more expensive.
Image stabilisation - Found mostly in Canon binoculars, this feature auto-corrects any jitters or shakes that can easily happen when you're using a high magnification - especially if you're holding your binoculars or sitting in a moving vehicle.
Binocular uses and recommendations
Ready to find the perfect binoculars for your needs? Visit your local Ted's store or browse our full range of binoculars online today.
What to Look For When Buying Binoculars
When buying binoculars, focus on four key factors: magnification, objective lens diameter, field of view, and build quality — see our full breakdown of binocular specs above for exactly what each one means and how to weigh them up against each other. Beyond the core specs, also factor in eye relief if you wear glasses, waterproofing for outdoor use, and whether porro or roof prism construction (covered above) suits your portability needs. Above all, match the binocular to your primary use case — what works best for stargazing will differ significantly from what suits concerts or hiking.
What Size Binoculars Do I Need?
Binocular size is determined by the objective lens diameter — the second number in a binocular's specification (e.g. 8x42 means a 42mm objective lens). Compact binoculars (under 30mm) are lightweight and pocket-friendly, ideal for travel and everyday carry. Mid-size binoculars (30–42mm) strike a balance between portability and light-gathering ability, making them the most versatile choice for most users. Full-size binoculars (50mm and above) deliver superior brightness and are best suited for low-light environments like dusk wildlife watching or astronomy. As a general rule: the larger the objective lens, the better the low-light performance — but the heavier and bulkier the binocular. Consider how and where you'll use them most before choosing a size.
What Makes a Good Binocular?
A good binocular delivers sharp, bright, true-to-life images with minimal eye strain — the optical quality and specs above cover most of what drives this. Beyond those fundamentals, look specifically for fully multi-coated optics and BAK-4 prisms, both of which produce meaningfully sharper, brighter images than budget BAK-2 alternatives, plus nitrogen-purged waterproof barrels to prevent fogging in changing conditions and a smooth, precise focus wheel. Budget models often cut corners on coatings and prism glass, so if image clarity is a priority, a reputable mid-range or premium pair makes a noticeable real-world difference.