(A special thanks to Kevin Hines and EdgewoodOutfitters.com)
How to Find the Perfect Binoculars
If you are looking to purchase a set of binoculars anytime soon, chances are you will be greeted by a ton of information and a lot of price differential for similar-looking models. Because there are simply so many types of binoculars available today, the options can seem truly daunting when coming at it with an untrained eye. This guide’s purpose is to provide insight into the different types of binoculars, their strengths and weaknesses, and the various features that factor into making a buying decision. For now, we will start with the basics:
Binoculars come in a variety of different sizes of magnification (numbers explained below) and allow in different amounts of light, depending on their intended use. While there are countless special permutations, we will be taking a look at the three most common ones in this guide. These include:
These types of binoculars usually have specifications that sit around 8 x 25 to 10 x 25 and are best suited for casual daytime activities that don’t require serious magnification. These types of binoculars are the lightest and smallest, making them quite convenient for many backpackers, although they tend to become quite a bit more uncomfortable after extended use than their larger brethren.
Commonly found at 7 x 35 and 10 x 32, these types of binoculars have extremely adaptable performance at a still-manageable size. Many backpackers can find these a bit large for their tastes, but still more swear by them. Observing wildlife or using these in a sports setting will be ideal, as these binoculars allow for above-average light transmission.
Full-size binoculars are commonly used for extreme wildlife observation and are also quite commonly used at sea. Usually sitting at 8 x 42 to around 10 x 50, this size is much too large for basic backpacking and other casual outdoor activities. The major advantage is that they allow much more light to pass through them, resulting in a steadier view and superior low-light capability.
The first number in a specification sheet for a pair of binoculars is the magnification number. For instance, in an 8 x 25 spec, a pair would have a magnification factor of 8. This means that objects viewed through the lenses would appear 8 times closer than they were in reality. Binoculars with magnifications greater than 10 can become difficult to operate freehand, due to the exaggerated movement shown when looking downrange.
Objective Lens Diameter
The second number in the specification is the objective lens diameter, which is measured in millimeters. This is the lens that is furthest from you and closest to your subject. This measurement, in its most basic form, determines how much light will be able to pass through the lens elements. If two binoculars with the exact same magnification but different objective lenses were to be compared, the one with the larger lens would perform better in a low-light scenario.
The exit pupil of a given set of binoculars is a measurement that will determine how bright an object appears when viewed through the lenses. If you are looking to purchase a pair of binoculars that excel at nighttime viewing, for instance, you will want to find a pair with a high exit pupil. This number can be found by dividing the diameter of the objective lens by the magnification factor. For daytime viewing, a lower exit pupil number will be fine, as the number itself is less important. The human eye narrows to around 2mm in bright light, and all binoculars offer at least this number to start with.
Eye Relief Measurement
This measurement refers to how widely the eyepieces on the binoculars sit when the entire field of view is present. Longer eye reliefs allow for greater comfort over time, enabling you to hold the binoculars further away from your face while still seeing clearly. This can be an especially important factor if you wear glasses. Finding an eye relief of 11mm or greater will allow you to operate the binoculars much more easily than those with lower numbers.
Field of View (FoV)
The field of view that a pair of binoculars offers relates to how wide your view will be through the lenses. Usually, a higher magnification means a narrower field of view. If you are looking for binoculars with which to bird watch, for instance, then it will be best to find a pair with a wide field of view, allowing you to find and track the animals easier.
Chances are that you are planning on using your new pair of binoculars out in the wilderness quite a bit. This can mean exposing them to the elements, whether rain, snow, or the open ocean. Waterproof offerings, for instance, usually utilize a system of O-rings that do not allow water, dust, or small debris to enter the lens element, keeping them safe and clean in the process. There are also versions of binoculars that are fog proof, achieved by placing an inert gas in a section of the lens element, canceling out any fogging effect created by cold air. There are even lens coatings that can be applied to the lenses themselves to reduce things like glare, while also increasing light transmission in inclement weather situations.
By this point, you should hopefully have a solid understanding of the basic principles and specifications that define the different types of binoculars available today, as well as their inherent strengths and weaknesses. This guide is meant to aid you in the purchasing process, whether you are looking for a basic set of inexpensive binoculars for casual backpacking and outdoor fun or an intensive, specialized set that will serve as a tool under extreme conditions. Whatever the case, understanding the features and attributes above will go a long way to providing the clarity you need to make the right choice for your individual needs.