Bigger is better, right? Well, sometimes. But in the story of optics and the eastern deer hunter, it’s quite the contrary. See, out east, or just this side of the Mississippi River, deer hunters are constantly finding themselves among the heavily wooded forests from Appalachia to the Adirondacks. Whether your choosing a riflescope for deer hunting or binoculars, higher maginfication doesn't mean better results. In these are grounds, an 8x magnification works best.
Higher the Power, the Less We See
Think of optics as an equilateral triangle where you have magnification on top, eye relief on the bottom left and field of view on the bottom right. When you go higher in one of these specifications, it alternately has an inverse effect on the other two. So, a higher magnification means a shorter eye relief and more narrow field of view. In the hardwoods on the right side of the country, field of view is pretty important when more often than not, it’s the flick of a tail or the white of a tine that first catches our attention.
In the dense deer woods, an 8x binocular provides a wider field of view that allows you to cover more ground, more quickly.
But, Find the Right Balance
Let’s say you find a binocular with an incredibly wide field of view, much greater than comparable products. Take a close look at the other specifications because chances are, that design is sacrificing one of the other key features. I have seen binos with an incredibly wide field of view, but the eye relief was so short that I practically had to press them into my eye sockets in order to see anything. The discomfort itself would not allow me to use the binocular for very long, essentially make the wide field of view a moot point. To sum it up, finding the right balance is the key when choosing a binocular that you can use it in a variety of conditions for extensive periods of time.
The best hunting binocular is well balanced in the three attributes above, including magnification, eye relief and field of view.
Depth of Field
In good light the naked eye produces a sharp, clear image, depending on your eyesight, from about six inches almost to the horizon. And not on a particular object that sits way out on the edge of the earth, but an obvious definition of space. When we look through a binocular, these parameters change significantly - the point at which everything is in focus and is equally sharp is pushed out by a factor equal to the magnification.
Our eyes are somewhat forgiving when it comes to focus and in fact can themselves alter the focus of the system within narrow limits. The zone within which the eye and brain can extract enough information to form a satisfying impression of the object is called the zone of acceptable focus, or the depth of field. Much like field of view, depth of field is greater on lower magnification binoculars. And the best binoculars for deer hunting, meaning one the hardwoods hunter is going to use a lot, should be comfortable to use in all lighting conditions with little straining of the eyes. This binocular is the one that comes closest to approximating the natural depth of focused attention of the human eye at any given distance.
Light Gathering Ability
The human eye is designed to gather or reject light based on our immediate lighting conditions. Your pupils can open five to seven millimeters at twilight while shrinking to almost two millimeters during the brightest part of the day. However, the light gathering ability of a binocular does not change, which is why knowing the difference between an 8x or a 10x is so important when choosing the best one for the part of the country in which you hunt.
A quality 8x binocular should give deer hunters an average exit pupil - the actual image in the eyepiece as it leaves the binocular to enter your eye - of just over five millimeters. A more technical definition of exit pupil is the diameter of the shaft of light (expressed in millimeters) that exits a binocular’s eyepiece and enters through the eye’s entrance pupil. Exit pupil is calculated by dividing a binocular’s objective size by its magnification. For example, 42mm/8x = 5.25mm or 42mm/10x = 4.2mm. This goes to show that at dusk and dawn, or in a dense forest, the 8x is your best bet to gather the last remaining light.
The following video explains what the numbers mean - tips to consider when choosing the best binocular for deer hunting.
If you have further questions as to why 8xs are the best binoculars for hunting deer, don’t hesitate to contact us at firstname.lastname@example.org or check out our Facebook page where we post frequent tips. We love talking optics and always enjoy hearing from the hunting community.