Skip to content

What Do The Numbers On Binoculars Mean?

Binoculars

When it comes to binoculars here’s what you need to know before your purchase.

Do you know what the numbers on binoculars mean? If yes, you’re a champion. If not, don’t worry, you’re still a champion, but we’ll help clear up any confusion.

From boating to bird watching to hunting, if you’re an outdoorsman, you probably own a pair of binoculars. It’s also probably safe to say, if you’re reading this, that the ins and outs of your binoculars may be a mystery. 

Hold on tight; it’s binocular education time!

What do the numbers on binoculars mean?

Understanding binoculars will no longer seem like a mystery. So let’s break it down. 

First and foremost, the numbers on binoculars are magnification numbers. 

You’ll see two numbers separated by an “x” (10×25, for example); the first number (10x) is the magnification power. The higher this number is, the closer objects will appear.

If the magnification number is 12-36×70, for example, then the magnification will make the object you’re looking at 12x to 36x larger.

The second number or the number behind the “x” is the size of the objective lens. 

Aperture (Objective Lens Size)

Objective lens size is also referred to as the aperture. The aperture expresses the amount of light that the lens can collect. What the heck does that mean?

The bigger the aperture, the brighter the image you’re looking at will be. 

HUNTER TIP: A high aperture number makes images in low light settings appear brighter (such as dusk/dawn). 

FoV

The Field of view or FoV is the area or width of the area you can see when looking through the binoculars. 

Often the binocular field of view number is expressed in feet. Suppose you see a degree in place of the FoV that is the area of view (AoV). They represent the same thing (width of the area you can see) just in either degree or feet. 

A good FoV number to look for in binoculars is around 300 feet.

HUNTER TIP: The better the FoV is, the less moving around you will have to do to find your object.
Man holding binoculars in the forest

Eye Relief Number

The eye relief number on binoculars is simply how far away your eyes can be from the eyepieces while still being able to see a full field of view through the binoculars. 

If you wear glasses, this is important. You’ll want a long eye relief or anything around 20-24mm for binoculars. This will help accommodate the extra distance between the binoculars and your eyes and still give you a full view.

Exit Pupil Number

Bigger is better when it comes to binoculars’ exit pupil number. This number needs to be bigger than your pupil. In most cases, an exit pupil number of 4mm will work just fine. 

Close Focus

The close focus number tells you what the minimum distance the binoculars need to focus on is. If the minimum focus or immediate focus is 5 feet, then that means at 5 feet, you can focus clearly on something.

Prism Systems

There are two types of prism binoculars; Porro prism and roof prism. 

Porro Prism Binoculars

Porro prism binoculars have a greater depth perception as well as a wider field of view. However, Porro prism binoculars tend to be a bit bulkier.

Roof Prism Binoculars

Roof prism binoculars provide a clear image; they typically weigh less and are more compact. However, the more complex prism design means a higher manufacturing cost.

Coating

There are several different types of coatings for binoculars, and each provides a benefit. Here are the most common:

Broadband multi-coating: This is the highest quality multi-coating out there. It acts to extend the range and enhance the view. 

Multi-coating: Multiple layers of coating on a minimum of one lens. This gives the lenses an increased level of image contrast as well as light transmission.

Fully multi-coated: All internal surfaces that touch air have multiple coated layers

Fully coated: A single layer on all surface that touch air

Single-layer coating: A single layer of coating on a minimum of one lense

Camouflage and Binoculars

Binoculars Guide Per Activity

When looking for a binocular, you should consider what it is you’ll be using them for. 

Are you going bird watching? Using them while boating? Will you be using your binoculars in low lighting? 

All of these functions or purposes factor into what kind of binocular to look for when buying.

Here is a chart with binocular specifications to look for depending on the purpose.

Purpose

Binocular Specifications

Boating

Waterproof. Rubber.

7×50, 7×42, 8×42, 10×42

Bird Watching

Long eye relief.

10×42, 10×50, 12×50

Hunting

Waterproof. Fogproof. Rubber.

10x, 12x, 16x

Low Light

7×50, 8×42, 10×50

 

How To Choose The Best Hunting Binoculars

When it comes to hunting, you want to make sure you have to best tools to help get the job done. So, naturally choosing the best binoculars is a necessity for spotting distant game. 

We recommend the Vortex Diamondback HD 10×42 binoculars for hunting. 

Vortex-Diamondback-10x42

They’re waterproof, fogproof, weather-resistant, compact, and are rubber-coated. The Vortex Diamondback binoculars are great for spotting game on the road or putting in your pack for hunting on foot.

They’re not the top of the line binoculars but for an all-around multi-purpose binocular, they’re a great bang for your buck. 

Binocular Knowledge Level: Expert

Congratulations, you’re now a lot closer to being an expert on binoculars than you were when you started! 

Now, if someone asks you “what do the numbers on binoculars mean?” you’ll be able to answer confidently, and then some. 

Happy outdooring!

Learn More

Subscribe to our Newsletter

Get the latest news and deals straight to your inbox!

Share this post with your friends

Leave a Reply

Your email address will not be published. Required fields are marked *