What Do Binocular Numbers Mean?

If you’re new to binoculars, you probably are wondering what binocular numbers mean. This is understandable since you want to choose the best binoculars with the right specifications so you can see the world around you from a brighter perspective.

We already did a whole blog post on how to choose binoculars.

But we find it quite necessary to dedicate an entire guide to deconstructing the complexities of binocular numbers for beginner buyers who are looking to get the best value for their binocular purchase. So, here, we break down the meanings behind these numbers.


Magnification power (10x50, 20x60, 12-40×40, etc)

One of the key benefits of a binocular is to magnify objects from far distances to make them appear larger, so they feel like you’re viewing them from a much closer distance. This is where magnification power, also known as binocular magnification, comes in.

You’ll see something like 10×50 or 12-40×40 in zoom binoculars.

In both cases above, the first number 10x and the first two numbers 12-40x represent the magnification power, respectively. So while the first binocular can be said to have a magnification power of 8x, the second has a variable magnification power of 12 to 40 times.

Higher zoom does not always translate to a better experience, though.

While a high zoom binocular will help you see images from far distances more clearly, the image quality will suffer as you zoom further into the object.


Zoom vs fixed magnification binoculars

From the examples we showed above, you’ll see binoculars with product description numbers such as 20X60, 12-40X40, or 12/40X40.

The first number(s) with the X is the magnification number, 20X and 12-40X or 12/40X, in the above cases. The first case with 20X60 denotes that you’re dealing with a fixed magnification binocular. In the second case of 12-40X or 12/40X, both of which mean the same thing, it tells a different story of a zoom binocular with both 12X and 40X magnification lenses.

Zoom lenses have advantages and disadvantages.

This type of binoculars makes it easy for users to zoom in and out into an object.

You can zoom out to spot or track an object or zoom in to see the fine detail, which can be quite valuable for hunting and other uses. However, binoculars like this tend to be a lot heavier and bulkier due to the added weight of the interchangeable lenses’ mechanisms.

What Do Binocular Numbers Mean

Objective lens size

If the first number(s) in your binoculars’ description refers to the magnification power, what does the last number after the ‘X’ mean? Here’s what it means;

These numbers refer to the diameter of your binoculars’ objective lenses in millimeters.

The lenses are big and are located at the end of your binoculars, always aimed at the sight you’re seeing. From the above examples, we can deduce that a binocular with 12-40X40 or 12/40X40 and another one with 20X60 have objective lens sizes of 40mm and 60mm, respectively.


So, what’s the significance of this?

Well, the surface area of your objective lens helps to capture light. This light is then transmitted to the ocular lens from where it then gets transmitted to your eyes. The larger your objective lens size, the more light your binocular will be able to capture. And the more light your binocular can capture, the brighter your final image or view will be. A larger objective lens size binocular is always better under low light conditions.


That said, what size should you aim for?

Generally, you want to go for those binoculars with 40mm objective lens size and above. Most binoculars with less than 25mm objective lens diameter size rarely produce clear imaging at significant zoom levels. Within 25 to 40mm, you’ll still be able to get something great enough for hiking. Above 40mm, you’ll get a binocular with excellent optical quality that you can use for hiking, bird watching, and more.


Field of view

You don’t get to see this number at all times.

Some binoculars do display them; some others don’t. When they are shown, these numbers are often expressed at a distance of 1000 meters. So, when you see something like 120/1000, what this is telling you is that your binocular has a field of view that is 120 meters wide at a distance of 1000 meters. A large field of view presents you with a much broader perspective. The higher the number is, the more you can see.


The numbers on binoculars carry significant meanings.

Although they may not tell the entire story of the binocular, they are a great indicator of what quality of output you can expect from your binocular. While you can’t afford to overlook these numbers when you’re in the market for binoculars, you can still consider our more comprehensive guide on how to choose binoculars for more in-depth information on choosing the right binocular for your intended use.

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