How to Choose Binoculars: A Beginners Guide

Binoculars are certainly a crucial tool for any outdoorsman. Although their basic technology dates back centuries, the ability to see beyond the range of the naked eye is immensely valuable.

Some people use binoculars for their work, others when hiking in the outdoors, or sometimes just to watch the boats in the bay. Because there are so many different purposes for binoculars, there are also a vast number of makes and models to choose from. Today we look at how to choose binoculars:

Salesmen can throw a whole galaxy of numbers at you, comparing coatings and degrees, but choosing a set of binoculars really isn’t that difficult.

There are three simple things in a set of binoculars that will determine how much they cost you, and what sort of tasks they will be good for.

They are:

  • Power of the mirror.
  • Size of the lens.
  • Quality of glass.

So when I pick up a set of binoculars that are labeled 10X42, that means the mirror inside is magnifying the image you see ten times, while the glass lenses have a diameter across the front of 42mm. All binoculars will have a value of Power-By-Diameter on them, and its the best way to tell the difference between units.

There are a variety of technical Binocular Terms that can come into play when we get down to making a final decision. But the first things you want to look at are the mirror and lens size.

Those two numbers determine the weight and role of binoculars.

For example: A set of binoculars that are 7X50 have a very low power with a very wide angle. They will be big, with 50mm worth of glass. This sort of mirror/lens combination is best suited for a boat, because the seven power mirror is much lower than most binoculars and good for scanning and stability.

A 12X25 set of binoculars will have a relatively high power, and a very small lens in the front like a set of opera glasses.

The Mirror:

At its most basic, choosing a more powerful mirror will affect three aspects of the image you see. It brings what you are seeing closer. A picture viewed at 12X will be bigger than at 8X. But it also narrows your field of view. Because we are closer to the object, we can’t see as much of what is around it. The other downside is that a stronger mirror will increase the shake you see. Small motions of your hand, heartbeat and breathing can all be seen when looking through an unstabilized magnified lens. This will vary from person to person, because some of us are more steady-handed than others.

The Lens:

Lenses follow some pretty basic rules. The more glass you have, the more light will be transmitted to your eye. This is especially important if you are likely to be using the binoculars in low light, as more glass will help when at dusk or when looking into shaded areas. A larger lens will also add to your field of view. But of course a larger lens can mean substantially more weight around your neck.

Quality of Glass:

The third factor that makes a set of binoculars is the quality of glass. This is tricky, because it is a subjective thing, without the hard numbers that let you make statements like: “Set A is 17% better than that Set B”

Quality of glass can be influenced by many things: glass origins, light transmission, coatings, cutting methods, internal gases, and many other technical concepts that we could get into.

But essentially, you can work off of a simple rule:


If it looks brighter to your eyes; then it is.

There is no statistic that can be more true than what you see with your own two eyes. I have to handle and look through a set of binoculars before I can even consider purchasing them.

Glass quality is largely what determines your price bracket.

I can find you a set of 10X42s that cost $50 and a set of 10X42s that cost $500. They may have the same mirror power and lens size, but the material that makes those lenses and mirrors is very different.

As a basic rule, you will see tiers of brighter glass coming from different countries, and the price will increase accordingly.

China – The basic glass. Anything under $200 will almost certainly be made in China.
Philippines – With substantial lessons from Japan, Binoculars assembled in the Philippines are generally of reasonable quality.
Japan – Home of the camera-giants, Japanese glass can be anywhere from $300 to $2000, and you will see a full range of glass quality in there.
Germany and Austria – Regarded as some of the highest crystal in the world, I have an entire article examining the German Brands and their often exceptionally priced optics.

American made optics can vary in quality between manufacturers.

Once you start thinking about binoculars in terms of the three defining attributes: Mirror, Lens, and Glass Quality, you will be able to easily differentiate one set of green rubberized glasses from all 35 other sets of green rubberized glasses.

Once you feel comfortable handling and differentiating between binoculars, you can start to decide what you like and what role you need it to fill.

Tags: , , ,

Trackbacks/Pingbacks

  1. Roles and Tasks: Where Different Binocular Sizes Shine - October 20, 2012

    […] by edwardo on September 13, 2012 in Resources Tweet Here we will go over some common uses for binoculars and which mirror and lens sizes fit best for each of those applications. Binocular sizes vary widely so if you need help determining what each number means, read our How to Choose Binoculars Beginner’s Guide. […]

  2. Vortex Binocular Warranty: A Game Changer in the Industry - November 19, 2012

    […] a long time, that meant it was time to buy a new set of binoculars. The whole choosing process starts again. But now, companies like Vortex Optics are changing the way manufacturer’s […]

  3. How the Law of Diminishing Returns Applies to Binocular Quality. - February 26, 2013

    […] our article on choosing your first pair of binoculars, we examined the three base components of a binocular: the mirror, the lens and the quality of […]

Leave a Reply