What Do The Numbers On Binoculars Mean?

If you are in the market for binoculars, you might have seen numbers everywhere. This is actually pretty common in these binoculars. There are symbols and numbers that mean different things. For example, 14-50 x 50. But what exactly does this mean?

What is the meaning of the dash (/) and hyphen (-)? What does 50 x 50 mean? Well, find out in this article!

What do the numbers on Binoculars mean?

The numbers on binoculars are generally in this format: Range of Magnification (separated by a hyphen) cross the largest magnification number. Still don’t understand it? Don’t worry. Let us explain.

Range of Magnification

Range of Magnification binoculars

The first two numbers of the pattern imply magnification power. The power of magnification is expressed in range. So, 14-50 means the magnification that is provided by the Binocular starts at 14, and then it goes all the way up to 50.

This is the range of magnification. This information is important because a person buying a scope will really need to see this range. They need to know how far the scope can see.

The more magnification a scope has, generally the scope is better. The keyword here is “generally.” One important thing about magnification is that more magnification isn’t always better.

Yes, most of the time, better magnification is great. In the 14-50 magnification range, 14 refers to the viewport zoom. As soon as the 14x magnification is surpassed, the binocular will start to provide a narrow view.

So, you will be able to see distant objects more clearly with 50x zoom but the view will be a bit narrow and you won’t really capture all the light.

Dash and Slash

Alright, we have covered the first two numbers in our previous example. You might have seen the numbers be separated by two things. They are separated by a dash (/) or a hyphen (-).

The dash indicates the lens zoon and the slash indicates the different magnification of the eyepieces. So, a 14/50 binocular will come with both 14x and 50x magnification which is a really cool feature.

There are design issues with both types of binoculars. The zoomable lenses will allow you to quickly zoom in to an object which is a handy feature of hunters. This feature also adds weight to your zoom capacity.

But this is yet another moving part that can break. Moving on to the next type of binoculars, there are interchangeable lenses that are heavy and bulky. These changing binoculars can provide you 10x zoom as well as 50x zoom.

You can carry only carry one type of lens if you want to. This can be beneficial for people wanting to travel light.

The diameter of Objective Lens

The last number present on your binocular will tell you the diameter of your objective lens. These lenses are big and fat. They are present at the end of the binoculars and these lenses do the actual job of making sure ample light enters the binocular. For example, in 13-50 x 50, the last 50 is the diameter of the objective lens.

Similarly, 13/40 x 60 implies 60mm as the objective lens.

So, what is the effect of the size of these objective lenses? Well, it is similar to the magnification power. There are some tradeoffs. A larger objective lens is going to let more light in. And the brighter image implies more colors. If you are using your binoculars for watching birds, the lenses will allow better viewing. Another caveat here is the weight of the objective lens.

The objective lens is the heaviest part of your binoculars. The tubes can be made out of lightweight aluminum and other parts can be made with plastic and rubber. And this can decrease the overall weight of the binocular but the lenses need to be made with high-quality optical glass which is a very heavy material.

As far as the diameter goes, objective lenses that are less than 25mm will not provide a clear picture in any zoom level. Move up to 25 to 40mm and you are probably looking at a pair of binoculars that is really good for hiking.

Once you move up the 40mm or larger lens, you can use it for bird watching. Cross the 50mm mark and the objective lens is perfect for hunting.

Field of View

All binoculars do not display the field of view number but they are still very important in the grander scheme of things. The field of view can be written is many different ways. The most common naming convention, however, is to express the width.

Also, good field view binocular can be used in whale watching.

A 1000 meter width can provide a zoom of up to 1000 meters. Therefore, a binocular with a FOV of 120/1000 will provide you with a field of view that can go up to 1000 meters in distance, and the actual FOV of the binocular will be 120 meters. A wider field of view means you can see more. The bigger this number is, the better it is.


So, there you have it. The meaning of all the numbers in a binocular is pretty easy to understand. The cryptic numbers are actually very simple. And if you think about it, they make sense.

It is very long to write, “the magnification of this scope ranges from 14 to 50 and it has an objective lens of diameter 56mm.” You can sum this up very easily to “14-50 x 56” and people with the knowledge on the topic will understand it. Let us revisit the symbols now and see what they mean for the last time then:

  • The Hyphen (-) separates the range. 14 – 50 basically refers to the zoom i.e. 14x to 50x.
  • The dash (/) separates the two different types of the objective lens. 14/50 basically refers to a binocular with the objective lens that has two different objective lens capacity of 14x and 50x.
  • The (x) separates the magnification range/variation with the lens diameter. The last number of the lens refers to the size of the objective lens. So, in 14-50 x 56, The 56 is the diameter of the lens.

References: https://en.wikipedia.org/wiki/Binoculars

Also check- Binocular Parts And Their Functions

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