When people are looking for good quality, versatile binoculars, they often invest in 10×50 binoculars. As they are capable of offering close-up views of almost any target with all kinds of lighting, they are a very good choice for almost all audiences, whether they are hikers, hunters, astronomers or birdwatchers.

But what should you look out for when choosing a 10×50 binocular? How to find the best 10×50 binoculars?

What do the numbers mean?

You've probably noticed that all binoculars are associated with two numbers, such as 10×50, 8×42, 15×70 or others. The first number indicates the magnification of the binoculars, while the second indicates the size of the lens, indicated in millimeters.

Magnification is easy to understand: it simply tells you how much your target will be enlarged through the binoculars. In the case of 10×50 binoculars, the magnification will be 10 x, so your target will appear ten times larger.

The second number, lens size, sometimes also called aperture, works differently, but is no less important. It refers to the large objective lenses at the end of the binoculars. These are the lenses you point at your target. The smaller lenses at the other end are the eyepieces through which you look.

The size of the objective lens determines how much light your binoculars can capture. The more light the objective captures, the more detail you'll be able to see. Similarly, if you're into astronomy, the larger the objective diameter, the better your binoculars are at detecting fainter objects.

Birdwatchers and anyone else who uses binoculars during the day won't notice much difference. However, if the birds you like to observe are nocturnal, if you use your binoculars for hunting in the middle of the night or if you're an amateur astronomer, a lens capable of capturing enough light will enable you to enjoy what you're observing even more, as you'll see more detail.

As usual, there's one small drawback: the larger the lens diameter, the heavier the binoculars can be, and weight is certainly a determining factor when choosing the right pair of binoculars for your purpose.

Why use 10×50 binoculars?

There's a good reason why 10×50 binoculars are the most popular: they can be used for almost any activity that requires the use of binoculars. The combination of this magnification with this lens diameter allows you to see your target up close and in a variety of lighting conditions.

This makes them an ideal choice for both day and night use, and for a wide variety of activities. For example, they are powerful enough to give you superb close-up views of birds, aircraft, marine life and various landscapes, while the 50 mm lens gathers enough light for birdwatching at dusk, stargazing or hunting in the dead of night.

How to choose the best 10×50 binoculars?

When buying 10×50 binoculars, there are a number of factors to consider, but here are 4 key ones:

• Weight
• Prism configuration
• Lens quality and coating
• Water resistance

Of course, the importance of each factor varies according to the activity for which you need to use binoculars. The weight and configuration of the prisms are important factors for all types of use, while the quality of the lenses is more important if you intend to use binoculars for stargazing, as it can make a big difference.

Finally, if you intend to use the binoculars during the day, water resistance may be a factor to consider, but will play no part if you're using your binoculars for astronomy. After all, you won't be able to observe the stars in the rain. However, always opt for binoculars that are at least water-resistant and, ideally, fogproof.

The weight

If you take your binoculars with you on hikes, if you enjoy birdwatching or if you intend to use your binoculars over an extended period of time, weight is certainly a determining factor.

Holding your binoculars in front of your eyes for a few moments doesn't usually cause any arm fatigue, but as soon as you hold them for longer than 1-2 minutes, or if you often have to pick them up again to use them, then you'll start to feel some signs of fatigue.

On average, 10×50 binoculars weigh around 800 g, but their weight can also depend on the prism configuration (see below).

Prism configuration

There are two types of prism configuration: Porro and roof. Porro prism binoculars refer to the traditional binoculars you've often seen in films and on TV. They have two large cylinders slightly offset from the eyepieces, giving the binoculars a W-shape.

Roof prism binoculars are a more recent invention and have been gaining in popularity since the second half of the 20th century. They are straight, giving binoculars an H-shape, and are designed to be lighter and more portable than Porro prism binoculars.

For this reason, they are often popular with hikers. However, the disadvantage of a more compact design is that the objective diameter tends to be smaller, usually reaching a maximum of 40-50 mm.

In addition to weight, there are a few other features to consider. Porro prism binoculars deliver a slightly higher image quality, and their manufacturing cost is generally lower, although the final price depends greatly on the manufacturer.

The biggest difference lies essentially in their weight and, consequently, their portability. With this in mind, if you're a hiker or intend to travel regularly, roof-top binoculars may be the best option for you. But if you're more intent on observing from a fixed location and want to prioritize image quality and a larger lens diameter, then traditional Porro prism binoculars are a much better choice.

(And if the binoculars you choose are large and heavy, you can always attach them to a tripod).

Lens quality and coating

The quality of optical instruments can make a big difference to the quality of the image you see. For example, binoculars sometimes exhibit chromatic aberrations, the famous rainbow effects you might see when observing a high-contrast object (such as the Moon.) This effect is difficult to eradicate completely, but is even more noticeable on inexpensive binoculars and those not produced by a reputable manufacturer.

There are a number of factors that contribute to image quality, the two most important of which are: the type of prism and its coating.

There are essentially two types of prism: BK-7 and BaK-4, the BK-7 being of inferior quality. Most of the time, the BK-7 is suitable, but for a hobby like astronomy, the BaK-4 is generally preferable (though not necessary). Amateur astronomers often use a star as a reference point for focusing, which can often make a big difference.

In any case, you should avoid all binoculars offering other types of prisms.

When it comes to the coating applied to the optics, it's a bit of a similar story. Anti-reflective coatings can improve the quality of the image seen through the eyepieces.

When buying binoculars, consider only the multi-coated (MC) and fully multi-coated (FMC) options. Again, as with prism types, these are the two preferred coatings offered by leading manufacturers. So we advise you to avoid all binoculars from unknown brands that state that their lenses are simply "coated".

What's the difference? Multilayer coating means that one side of a lens has been coated several times, while other lenses have been coated only once on one side. Fully multi-coated means that all the faces of all the lenses have been coated several times.

Water resistance

Although most binoculars from reputable manufacturers are water-resistant, some might argue that having waterproof binoculars is really a matter of personal choice. As mentioned above, in reality, it depends on what you're going to use your binoculars for.

If you're a birder or hiker and need to use your binoculars in all kinds of weather conditions, getting waterproof binoculars will probably be a good idea. This is especially true if you plan to use them near water sources, such as a river, or on the beach.

On the other hand, if you're going to use your binoculars for astronomy, waterproof binoculars won't be much use to you. After all, you won't see much if the sky is overcast or it's raining. However, it's worth considering anti-fog binoculars, as temperature and humidity could fog up your optical instruments.

Frequently asked questions