Binoculars are a birdwatcher’s best friend. They allow you to get close-up views of distant objects without having to actually get close. While they all perform the same basic functions, not all binoculars are good for bird watching. Features like build-quality, optical quality, and lens coatings all play a role in determining whether a pair of binoculars is good for birding.
In this guide, we’re going to cover the features that make for a great pair of birding binoculars, including the basics to look for when you’re starting out. We’ll also recommend some of our favorite pairs, including the best options for birders on a budget, those looking to upgrade, and the best pair overall.
What to Look For
Size
Whether you’re staking out a migration hot spot or trekking up a mountain to find a specific species, you may find yourself holding a pair of binoculars up to your eyes for extended periods of time. The physical size, weight, and balance of the binocular should be considered when picking a pair for yourself. Where your hands fit on the pair can greatly affect the feel and balance of the binocular as well.
A pair like the Nikon Aculon A211 8x42 uses a more traditional porro prism design. The result is a generally less expensive binocular that can offer greater depth of field and a wider field of view. This all comes at a cost to size, with porro prism systems being generally larger than comparable roof prism designs, like the Nikon Monarch M5 8x42.
Magnification/Objective Lens
8x42 and10x42 binoculars are the ideal choices for birding. The first number in these labels refers to the magnification, and the second represents the size of the front element, known as the objective lens. Why 8x42 and 10x42? These options offer the perfect mix of light transmission and compact size. They won’t weigh you down and they won’t get in the way, and at no cost to clarity and brightness.
Exit Pupil
This refers to the size of the focused light that reaches your eye. Exit pupil diameter is determined by the objective lens and magnification. To find out what the exit pupil is for a particular binocular, you should divide the objective lens diameter by the magnification. If we take a 10x42 binocular and divide 42 by 10, we find that our binocular has a 4.2mm exit pupil diameter.
Your exit pupil should always be larger than the pupil of your eye. It’s important to note that the pupil of the human eye ranges from 1.5mm in bright light to 8mm in the dark. Why is this important? If the exit pupil is smaller than your pupil, it’ll appear as if you’re looking through peepholes.
Build Quality
Nowadays, binoculars are made of reinforced polycarbonate, aluminum, or the more durable magnesium-alloy. While polycarbonate can be strong, its components can wear down with time. The results could be a loose bridge hinge or even wobbly lens elements. Magnesium is the better material for long-term durability. The weight is comparable to polymers but significantly more robust. It’ll hold up to years of abuse and as a bonus, is corrosion resistant. The rubber coatings on most binoculars will also protect the chassis from scuffs and scratches.
Weather Resistance
Most binoculars on the market today have some form of weather resistance. Additionally, the objective lenses are generally fog proof. This is accomplished by filling the space between the optics with nitrogen or argon gases and sealing the housing with O-rings. It’s worth mentioning that some pairs are weather-resistant while others are fully waterproof to a certain depth. While not designed to be submerged, accidents happen.
A weather-sealed pair will allow you to use your binoculars worry-free during light to moderate rainfall. A fully waterproof pair can survive a deluge and can also survive being dropped in the water up to a certain depth. For instance, the Leica Trinovid HD 42 binoculars are watertight to a depth of 13.1 ft. Check the rating of the pair you’re looking at and make your decision based on based on the conditions you expect to be using them in.
Optical Quality, Coatings, and More
The better the glass, the better the viewing experience. Anti-reflective coatings and specialized glass will make for brighter, sharper images and in some cases, fatigue-free viewing. This is important for longer outings as any duration looking through glass can lead to eye strain. Some higher end binoculars take this into account and maximize the amount of light that can travel through the entire optical path and to your eyes such as. Some brands even offer droplet and scratch resistant coatings to make for easier cleaning like the SWAROCLEAN system found on Swarovski optics like the 8.5x42 EL 8x42.
Minimum Focus Distance
Some pairs will allow you to focus as close as 5’ away. The significance of this feature depends greatly on your style of birding. If you prefer to count migrating hawks over Cape May, then this might not be a deal breaker for you. However, if you’re the type of birder who likes to explore local parks, you may find this feature useful when spring warblers are foraging in some trailside shrubs.
