Seasoned hunters know that using the right binoculars is right up there in terms of importance with your rifle. Making your targets easier to see and evaluate, plus being able to easily scout terrain will make your hunts that much more successful and enjoyable. Today, we’re going to go over binocular basics: how they work and some of their key features. From magnification power to eye relief, we’re to figure out what the specs and options mean and what you’re going to want to look for in your hunting binocular.
How Binoculars Work
Binoculars use two convex lenses, one placed in front of the other, to help you see at a distance. A convex lens is thinner on the outside edges than in its middle. This makes it so that when light enters the lens, it bends towards the middle and puts the distant rays into focus. The first convex lens, also called, objective lens, catches light from the object and makes a focused image a short distance behind the lens. The second lens is actually the one to pick up that image and magnify it.
When light rays pass through a convex lens they cross over and create an upside down image. Two prisms are added in between the barrels containing the lenses to rotate the image 180°. Binoculars can be so large and heavy because they are accommodating these prisms.
To figure out which kind of binoculars are best for hunting, we’re going to break down at some features of binoculars to see how each aspect individually plays into choosing the best hunting binocular for you.
Binoculars are identified by two numbers- the magnification power and the lens diameter. Magnification power refers to the first number when looking at binocular identification specs. For our purposes as hunters, this will either be an 8 or a 10. All this number means is that the object you’re looking at will either be 8 or 10 times magnified to your unassisted eye. Binoculars with a magnification power greater than 10 amplify the movements of your hands which makes steady viewing difficult and adds unnecessary weight to your pack and hands.
The diameter of the objective lens is the second number in this 8 x or 10 x equation. The diameter of this lens establishes how much light the binoculars can take in. The larger this number, the more light can get in, and the better the view. This number is especially important as hunting in early morning and late afternoon or early evening offers low visibility. The downsides to a bigger lens as you might imagine, are heavier weight and higher price tag.
Field of View
The field of view (FOV) number tells you the width of the area that you can view at a glance 1,000ft from where you are. A higher magnification power will produce a narrower field of view and a low magnification will give you a wider FOV. A wider FOV is best for identifying birds or any game that’s requiring you to look over large areas. For a wider FOV consider binoculars at 8 x 30, 32, or 42.
There are three general sizes of binoculars: Full size, Mid-Size, and Compact. You can’t go wrong hunting with mid-sized binoculars. They strike a good balance between price, size, and light transmission. Their specs are around 8 x 25 and 10 x 25 and have an objective lens around 32mm.
Of the 8 x and 10 x binoculars, there’s some debate on which is preferable. If you’re in a situation where visibility is limited, like the woods, binoculars around 8 x 42 will be an effective and lightweight choice. Something around 10 x 42 would be better for hunting in open fields, but it will be heavier.
The exit pupil number is measured in millimeters and is found by dividing the diameter of the objective lenses by the magnification number. The exit pupil will show how bright an object will appear in a low light situation. A higher number will result in brighter images and conversely a lower number will results in darker images. Exit pupils measuring 5mm> are great for low light situations- dawn, dusk, or under heavy tree cover.
Glasses wearers pay attention, the eye relief spec is most useful for you. It’s the distance in millimeters between each eyepiece and your eyes, where the image is still in focus. An eye relief of 11mm or more is going to increase your comfort by allowing you to hold the binoculars away from your face which you need to do if you’re wearing glasses.
When light enters the lenses, some of it is reflected away, diminishing the brightness of the image. Coating the lenses reduces reflection, increases light transmission, and ensures you have that quality image you need for the hunt. There is a wide variety of lens coating options out there and they will cost more, unfortunately if you’re looking to be economical.
Waterproof and Weather-Resistant
Waterproof binoculars are best for boating but for the average hunter, weather-resistant binoculars are more worth considering. Weather-resistant binoculars are designed to protect against light rain but not against submersion.
Like eyeglasses, binoculars will fog up as you move between temperatures. It’s not only annoying but can cause long term damage to the binoculars if moisture gets trapped.
So how are binoculars made fogproof? The air inside the optical barrels can be filled with inert gas which has no moisture. Because there is no moisture, it can’t condense and fog up internally. Externally, the binoculars may still fog up.
Final Thoughts on Hunting Binoculars
Whether you’re hunting on open plains or in heavily wooded forests, there’s a binocular that’s going to be useful to you. Remember: a mid-sized binocular is best to start your search with because of it’s light weight and versatility and a lower magnification power is going to produce a wider FOV which is also the most generally useful. Streamline your process, perfect your system, consider packing a pair of binoculars along for your next excursion out.