Buying Guide Binoculars


Buying Guide Binoculars

What is a Binocular?

In simple terms Binoculars are two optical devices that provide a good depth effect, and are used with both eyes. Basically binoculars are two small telescopes fitted side by side. When looking through a telescope the image is inverted and appears upside-down and back-to-front. Within a binocular each telescope has two prisms between the eyepiece, thee prisms correct the image making them right-way-up. Binoculars are used to make distant objects appear brighter and larger, enabling you to see them more clearly. 

What are Binoculars used for?

There is a wide variety of use for binoculars from hobbies, sporting to outdoor activities. Most commonly binoculars are used for nature watching (birdwatching, whale watching), boat watching, sporting events, and star gazing. Different binocular specifications are beneficial for different activates as it ultimately enhances the experience. 

What are the numbers on a binocular?

There are typically two numbers listed on any binocular separated by an “x” – e.g. 8x25. The first number before the “x” is the magnification, or how many times closer or larger the object will appear through the binoculars.

For example: an object viewed from 100m away through a 10x magnification will appear to be about 10m away.

If the binocular magnifications have two numbers, for example: 10-30x. This means that the binoculars have a variable magnification, enabling you to switch from 10x magnification to 30x magnification and everything in between. These are often referred to as zoom binoculars.

The number after the “x” is the size of the objective lens in millimetres. The larger the number (or objective lens) the more light pours into the binoculars, making the image brighter and clearer. The Smaller the number (or objective lens) the more restricted the light flow, however these binoculars are typically lighter, more compact and easier to carry and hold.

This is why the usage of the binoculars is important, not just going for the largest numbers! 

What is the ideal magnification of a binocular?

Magnification is not a constant variable; the intended usage very much dictates the ideal magnification of your binoculars. For most purposes, a 7x, 8x or 10x magnification is ideal – because they tend to be smaller, lighter and easier to carry. They are also great for kids to get into nature viewing! Higher magnifications are normally used with a tripod due to their size and weight, and are used for viewing very distant objects, such as whales, boats, and celestial objects at night. Before purchasing a pair it’s important to consider the frequency of use, the location and purpose to get the most out of your binocular. 

What lens size should I choose in my binocular?

Like with magnification, this depends on what you intend to use your binoculars for. 

Larger Objective Lens

Smaller Objective Lens

Let more light through

Let less light through

Better for low-light conditions

Better for light conditions

Heavier & Larger

Lighter / Smaller/Compact

Harder to carry / less portable

Easier to carry / more portable

Higher magnification

Lower magnification

May require tripod or body harness

Easily held or worn around neck

Ideal Exit Pupil* 4-8mm

Ideal Exit Pupil* 2-4mm

 * Exit pupil –is the small disc of light that is projected into your eyes and is directly correlated to the objective lens size. As a rule of thumb, if you want to use your binoculars during the day, then an exit pupil of 2-4mm is ideal. If you want to use your binoculars in low-light conditions, then an exit pupil of 4-8mm is preferable. 

What are the coatings on binoculars?

All binoculars have at least some coatings on some of the lenses that are designed to reduce reflections and therefore increase the brightness and clarity.

  • Fully Coated optics: means that all air-to-glass surfaces have been coated.
  • Multi-coated optics: means that one or more of the lenses has coatings applied with multiple films. This improves the brightness and contrast of the image when compared to Fully Coated optics.
  • Fully Multi-coated optics: means that all air-to-glass surfaces have received multiple layers of film, which again improves the brightness and contrast of the image compared to Multi-coated optics.

As a rule, we recommend purchasing binoculars with the highest coating rating within your budget, as this will provide the best quality image and give you the most out of your binoculars.

Why don't all binoculars look the same?

Binoculars use one of two broad types of prism configurations: Roof Top or Porro (or Reverse Porro, which is a variation of the Porro type).
While the specifics are very much up for debate in the hobby community, it is generally accepted that Porro binoculars provide a greater sense of depth when viewing objects up close, so are often favoured by nature watchers. Roof top prisms, however, tend to be more compact and easier to carry. Diagram below shows the basic difference between the two types of prism.

If this is your first pair of binoculars, then you won’t need to worry too much about which type you choose.

What is the prism glass and why does it matter?

All binoculars are constructed using glass prisms to reduce their overall size. These come in two different types of glass: BK-7 (or borosilicate) glass and BaK-4 (or Barium Crown) glass.
The difference between the two is that BaK-4 glass has a higher density than BK-7, which reduces the scattering of light inside the binoculars. In practice, this means that BaK-4 glass is generally clearer and crisper around the edges of your field of view and is particularly noticeable in low-light conditions.

Which Binocular is right for me?

Below is a break down by type of activities and what binoculars are best suited to that activity, please note we have included all for your knowledge and reference, not all are currently available on our website. We range the most versatile and common binoculars for beginners and naturists.

Bird & wildlife watching
A small compact binocular Is best for bird watching, it is important to pay attention to the weight especially if you're taking it walking/hiking! Ideal magnification would be 10x, with an objective lens 25-40mm diameter. Certain coatings and lens types may make the image clearer, especially when observing wildlife from a far. 
Recreational i.e. Sport/Boating/Racing Similar to Bird/Wildlife watching compact binoculars are ideal for recreational use. Magnification of 8x or 10x is ideal. An objective lens 21-25mm diameter will allow sufficient light for clear images. Fast paced sports require a focus free or self-focusing binocular to enhance the experience. For prolonged use, weight needs to be a key consideration. Where water is present such as boating, consider a water proof binocular, these are O-ring sealed and nitrogen purged for reliable fog proof, waterproof performance (they will not float if dropped into water). 

Star Gazing, Astronomy and long distance Larger objective lens is required when intending to use your binocular in low light or for long distances, an objective lens of 40+ is ideal. If you are looking for a mid-size binocular consider purchasing one with a zoom to enable to you magnify the image further. When purchasing a large binocular, we recommended purchasing a tripod adapter and tripod, for stability and weight reduction. Another consideration may be a harness if you’re on the go. 

Compact Most commonly used binocular as it is convenient, light weight and lower cost. These are a great choice for bird & wildlife watching, sporting & racing events, theatre, concerts and while travelling. Compact binoculars are also a great choice for children as they are low weight. 

Monocular Put simply, a monocular is half a binocular. They are used to view objects in the distance making them appear closer whilst only using only one eye. They are best suited for hiking where you only have one arm free and want quick access to view distant wildlife, golfing and when wide field of view is required. They are also suitable for perspective views using both eyes open for the widest field of view. Most night vision instruments are also monocular, these are slightly larger and heavier with built in true night vision technology. 

Suitable for Children Any compact binocular is suitable for children. Magnification of 6x or 8x is ideal. Choose a light weight small binocular with a strap, this will protect the binocular from accidental falls.

Do I need any accessories?

Larger high-powered binoculars typically have the ability to mount onto a tripod for prolonged viewing sessions and increased stability. In this instance a tripod adapter and tripod can be a very useful accessory.

Other than that binoculars are one off investment for years of enjoyment and discovery.

What can go wrong?

Realistically not much can go wrong with a binocular, apart from being uncollimated - which typically occurs when a binocular is dropped or knocked. Uncollimated Binoculars show double or overlapped vision and that is because the light is no longer parallel due to misalignment/shifting of the prisms/lenses.

Note: Uncollimated binoculars are not covered by warranty unless they arrive that way, we highly recommended that as soon as you receive your binocular you open it up and have a look through to make sure there is nothing wrong with the vision, then immediately contact us with any issues and we'll happily rectify. 

Like with any mechanical product, moving parts can get damaged or have faults. A zoom binocular (although rare) may also have an issue with the zoom mechanism. 

Other than typical wear-and -tear (fading, scratching etc) not much should go wrong with your binoculars if you look after them. Store out of direct sunlight to avoid premature aging of plastics and rubbers and away from damp conditions to avoid condensation.

Missing/damaged parts - check everything is included and intact when you receive your order, if anything looks odd or is not there contact us (include clear photos and descriptions where possible to speed up the process)

WARNING – when using any magnifying device during the day especially a high magnification item such as a Binocular NEVER LOOK DIRECTLY AT THE SUN, this can cause permanent damage or blindness. Always supervise children when using a telescope/spotting scope, especially during the day.

Take a peek at our range and if you have any further questions get in touch!