How To Choose Binoculars For Travelling (Best UK Guide)

There are so many binoculars to choose from and it can become very confusing very quickly if you don’t know what to look for. This article gives you free, independent advice on what binoculars will be best for your travel needs. We’ll explain all the technical terms in plain, easy to understand English, to make your buying experience a piece of cake.

What Size Binoculars Do You Need?

Binoculars come in three sizes and are classified using the size of the objective lens. They run as follows;

• Compact
  Compact binoculars have an objective lens of lower than 30mm
• Mid-size
  Mid-size binoculars have an objective lens of between 30 to 40mm
• Full Size
  Full size binoculars have an objective lens of greater than 40mm

With modern binoculars full size doesn’t necessarily mean large, cumbersome, bulky binoculars. Modern technology has removed the need for massive casings. However, you should be aware that larger objective lens increase the overall weight of the binoculars incrementally (the larger the lens, the heavier the binoculars will be).

How To Choose The Best Binoculars For Travelling

The first hurdle to overcome is which type of binoculars you want to buy. There are two types and they both have good and bad points, and they’re easy to tell apart. They are Porro prism or roof prism, which unless you’ve already done some digging, will mean absolutely nothing to you.

Porro Prism Binoculars

These are the classic shaped binoculars and are somewhat in the shape of an M with their small eyepiece spreading out to a large bulging middle and then out even larger to the big lens. They were invented in the 1850s and haven’t really changed too much since. Porro prisms work by allowing light to enter through that large lens at the opposite end to your eyes which in binocular terminology are called the objective lens. That light is then passed through two sets of off set prisms that magnify the image and turn it back the right way so when you look through the eyepiece it looks closer and upright.

The prism setup can get knocked out of alignment with not too much of a bang, which is worth remembering if you are inclined to be a bit clumsy. If the prisms do get misaligned you will suffer from eye strain, which leads to headaches and even migraine.

Roof Prism Binoculars

These look like the letter H with their slim straight tubes joined in the centre by the focusing twist knob. As the name implies, roof prisms are used to magnify the image that enters with the light through the objective lens. Roof prism binoculars are smaller and lighter than Porro prisms but a decent pair will set you back more than the equivalent Porro prism pair would. That’s because all the precision work needed to create roof prisms costs extra to make.

These dominate the market nowadays and with good reason, they are lighter, smaller, and yet just as powerful as Porro prisms and for travelling a pair of roof prism binoculars will probably suit you best. They will take up far less space in your bag, and weigh considerably less too.

What You Need To Know About Prisms And Binoculars In A Nutshell

• Roof prism binoculars are smaller, and easier to carry when travelling
• Roof prisms require specialist equipment and fitting, so they are more expensive
• Porro Prisms are cheaper to make, but are heavier, bulkier, and larger
• Porro prisms can get knocked out of alignment easily

To summarise, they are both good but it depends on what size you prefer, how accident prone you are, and how much your budget allows. For the price of a decent pair of roof prism binoculars, you could expect to get a top of the range pair of Porro prism binoculars.

What Else Do You Need To Know?

You will encounter a lot of jargon when reading about binoculars, so let’s clear up some of that jargon so you can understand what’s being shown to you.

What Is Eye Relief?

Put plainly, eye relief is being able to see a clear image through the binoculars when you hold them further from your eyes. This is of great importance for glasses wearers or those who wear sunglasses while using binoculars. The eye relief should be printed on the box and 12mm is fine for travelling binoculars. But if you wear glasses you will need at least 16mm more is better.

What Magnification Do You Need For Travel Binoculars?

This will be printed on the actual binoculars along with the objective lens size (more on that below). It will look something like 8×32 or 10×42. The first number is the magnification size. So taking our first set of numbers, the 8 followed by the X tells us that that particular pair of binoculars has a magnification of 8 times. Which in plain English means you’ll see the image through the binoculars 8 times larger than it appears with the naked eye.

Another point about magnification is that too much results in a shaky image. This is because we all shake when holding an object out in front of us. We don’t usually notice the slight shake but under high magnification, that shake is highlighted. So anything above 10x magnification will make that shake more apparent.

What Size Objective Lens Do You Need For Travelling ?

This is the lens closest to the object and its size is represented by the second set of numbers in millimeters. So in our previous example of 8×32 the objective lens is 32 mm in diameter. Now this is where it gets interesting, because the higher the objective lens number, the more light that is allowed into the binoculars. The more light that enters the binoculars the brighter the image and the clearer it will appear. 

But the larger the objective lens, the heavier the binoculars will be. So you’ll need to have a trade off, because nobody wants to struggle to hold heavy binoculars for too long.  It really depends when and how you’re going to use your binoculars, if you’re going to use them in full sunlight a lower objective lens will do fine. But if you intend to use them in low light conditions, then you’ll need a higher objective lens.

For Travelling Binoculars We Would Suggest 8×32 or 10×42 To Be The Best Choice

What Does Exit Pupil Mean?

When you hold the binoculars out in front of you at arm’s length and look through the eyepiece, those bright discs you can see are the exit pupils. This should be larger than your own pupils once they’ve settled in dark conditions. The average size of a human pupil at the age of 30 is around 7mm. This number decreases every decade by 1mm so by age 50 your exit pupil will be 5mm and so on. As a general rule of thumb, the larger the exit pupil, the better (as long as it’s over 7mm).

What Is The Field Of View (FoV)?

The field of view is how much you can see through the binoculars from left to right. It will be expressed on the binoculars in one of two ways. Something along the lines of 6 degrees or 315 feet at 1000 yards (they’re both the same). The more field of view you have the better really and anything between 6 and 7.5 degrees is good, 7.5 degrees is around 394 feet per 1000 yards. One degree is equal to 52.5 feet so to calculate any degree into feet per 1000 just multiply the degree by 52.5 to get the feet per 1000 yard calculation. For instance;

6 degrees is equal to 52.5×6=315 (feet per 1000 yards).

And so on.

What About Waterproofing?

This depends on where you are travelling, but we live on a planet that is made up of 71% water (or thereabouts) so at some time you will get rained on. As long as your binoculars have been waterproofed to a high industry level, they will be fine. The industry set up a coding system to take the confusion out of the erroneous claims of weather-proof and water-resistant. But their own coding can be confusing too, so without boring you with the details, a value of IPX6 and above will keep the weather out.

Is Fog Proofing Necessary For Travelling Binoculars?

Along with waterproofing, fog proofing is another worthwhile feature to have on your travel binoculars. Binoculars fog up because of moisture inside the lens tubes reacting to temperature changes. Like coming from a warm bus terminal out into the cold air.

To overcome this problem, binocular manufacturers have come up with a way of purging the air from the lens tubes and filling them with an inert gas like nitrogen or argon. As these gases contain no moisture, they cannot react to fluctuations in temperatures and so don’t fog up. As an added bonus, once these gases are sealed in, nothing else can enter. This keeps the binoculars dust, microbial debris and mould free.

 What About Lens Coatings?

This can be another minefield unless you know how to navigate it. Lens coatings are a great feature to have but, there are so many different types of coatings, and so many misleading claims too. The bottom line and all you need to know is, the only coating worth having for travelling is Fully Multi-Coated Lenses. This means every lens is coated multiple times to reduce glare, improve light transmission, colour and brightness.

Do You Need A Protective Coating For Travelling Binoculars?

Protecting the binoculars with a strong rubber coating is definitely worth considering. There will come a point when you will accidentally drop your binoculars. When you do, having them coated in a strong, robust, impact resistant outer casing will save any serious damage. This is of extra importance if you have decided to go with Porro prism binoculars, but it’s handy to protect your investment in all cases.

What Are Image Stabilisers?

This comes courtesy of the camcorder technology and is well worth considering if you intend to do lots of travelling in motor vehicles. Image stabilisers detect and correct any motion from the image to give you a clear view. There are two drawbacks to having image stabilisers and they are;

• Extra Weight To Carry And Hold
• The Batteries Will Need Replacing Regularly

A Note For Backpackers

If you are backpacking or have limited space when you’re travelling, we recommend a compact pair of binoculars. You will lose some light advantage but they are lightweight, will take up less space and still give you great viewing power. We would suggest a good pair of 8×30 binoculars will fit in your pack with no trouble.

How Much Will A Pair Of Travelling Binoculars Cost?

The first piece of advice here is to draw up a list of the features that are important to you. Then find a well known brand, search for the pair manufactured by that brand that have all of those features then compare prices online. To give you an idea an OK pair of binoculars will set you back from £50 to £80. A top of the range pair will cost you around £1000 but you can expect to pay around £200 to £250 for a good pair of travelling binoculars.

Buyer Beware

One more piece of advice, don’t get suckered into a pair of those advertised on some of these online shopping places. Which appear to have all of the features, excellent numbers for magnification and objective lens “fully coated” “water resistant” and can be yours for the princely sum of £14.95 with free postage. These will ultimately let you down, or at least give you a headache. If it seems too good to be true, then it usually is too good to be true.

Those cheap binoculars are made by underpaid, inexperienced and unqualified staff. Using inferior, outdated parts. There was never a truer expression that “you get what you pay for” in terms of binoculars.

Frequently Asked Questions