What Do the Numbers on Binoculars Mean?

If you are an outdoor enthusiast, you know how important binoculars are. You will find them handy for a wide selection of applications both indoors and outdoors. Whether it is bird watching, hunting, wildlife watching or urban exploration, binoculars will enhance your vision and ensure that you don’t miss anything.

Whether you are purchasing your first pair of binoculars or you are looking to get an upgrade, getting a new pair of binoculars is always exciting. And with so many models available on the market, it is hard to miss a model that suits your needs perfectly.

When buying binoculars, you will notice that each model has some numbers printed on the side. If you are new in the market, you are probably wondering what these numbers mean.

In this post, we will help you understand the number in your binoculars better so you are able to pick a pair that works best for both your needs and preference. Let’s get started.

What Do the Numbers on Binoculars Mean?

The numbers displayed on your binoculars provide key information regarding a wide range of information. Each binocular has its unique numbers which sets it apart from the rest and makes it unique for specific activities. Let’s now take a look at these numbers in greater detail.


Magnification is a unique number that sets binoculars apart. It is normally the first number that you will find on the binocular’s configuration. This is one of the first and most important things you should consider when choosing binoculars. It determines how far you will be able to see and what activities you will be able to use the binoculars for.

With binoculars, a larger magnification will let you observe objects at a distance, but it is not always the best. High power magnification makes binoculars hard to hold steady and the slightest handshake will affect your view.

If you are looking to buy binoculars with extreme magnifications that is 12x and above, ensure that you stabilize them first on a tripod or any other solid object before you start viewing your targets. When you do so, you will be able to keep them steady all through.

The best middle-of-the road standard for binoculars are those with 8x or 10x magnification. 10x models provide higher zoom to help you observe targets at longer distances. On the other hand, 8x binoculars provide more image stability control. They are also the best binoculars for all-round application.

Objective Lens Diameter

The number after magnification represents the size of the objective lens, also known as the aperture. The objective lens is an important part of every binocular. It dictates the amount of light the optics are able to collect.

Generally, the larger the objective lens the more light the binoculars collect. This results to production of brighter  and better quality images even in low light conditions. However, wider lenses increase the size and weight of binoculars. Binoculars with wider objective lens are also more expensive.

A model with 40mm to 42mm will be sufficient for a wide range of outdoor applications. It offers the perfect balance between weight and optical performance. However, if you are looking for a compact pair of binoculars that is portable and easy to carry everywhere you go, consider looking for a model that has a smaller objective lens of between 30 to 40mm.

Field of View

Field of view refers to the full area that you can see through the binoculars without moving them around. Having a large field of view means being able to spot your targets with ease and tracking them as they move around.

Field of view is represented either as an angle or in numbers either in feet per 1,000 yard or meters per 1,000 yards. Typically, a model that offers 300 to 375 feet at 1,000 yards is adequate for general use of binoculars.

You should also know that magnification affect the field of view. These two features are inversely related. A high magnification means a narrower field of view and vice versa.

Eye Relief

Another number that is important to consider when buying binoculars is eye relief. It tells you how far your eyes will be from the eyepiece.

Eye relief is mostly important if you put on eye glasses. You will want the binoculars to offer an eye relief that is long enough to allow you to view your targets comfortably without removing your glasses.

A long eye relief of at least 15mm is recommended for all users, with and without eye glasses. A model that offers a long eye relief will also aid in quick target acquisition and reduced eye fatigue during lengthy glassing sessions.

Exit Pupil Number

Exit pupil is another important number you need to know about whenever you are choosing binoculars. For anyone who is buying their first pair of binoculars, exit pupil refers to the small column of light that you are able to see through the binoculars when you hold them at a distance from your face.

To get the most out of your binoculars, you need to get a model that offers a wider exit pupil compared with your pupils. The wider the column is, the more light your eyes will register when you are using the binoculars.

But this varies from one person to the other depending on their eyesight. Generally, the pupils of senior people don’t dilate as much as those in younger adults. So, the older users will want an exit pupil that is not only smaller, but also more concentrated.

To know the exit pupil of your binoculars, you should divide the size of the objective lens by 10. For instance, a 50mm binocular has a 5mm exit pupil. Such a pair will be great for a younger individual. But for a senior or elderly user, they will get much more if they use a compact pair with a much smaller exit pupil, rather than a full-size model.

Close Focus

Lastly on our list is the close focus. The amount of close focus in any binoculars tells you the minimum distance the binoculars require to focus. For instance, a 13 feet close focus means that you can use the binoculars to get a perfect focus an object that is as close as 13 feet.

Close focus is particularly important for birding and wildlife watching. It will help you get the perfect image views of objects at close distances.

Final Thoughts

What Do the Numbers on Binoculars Mean? We hope that the information listed above has answered this question. Understanding these numbers will help you find the binoculars that is right for your needs.

Get a model with a large aperture if you are looking to observe objects at longer distances, and a smaller aperture if compactness and portability is what you are after. Also ensure that you get a pair that offers an ample eye relief and a wide field of view to get the most out of your outdoor adventure activity.

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