Choosing the Right Hunting Binocular
Traditionally a surrendering military officer hands over his sword or, in more recent times, sidearm. But when U-Boats were captured during World War II, victorious allied naval officers often demanded that German captains relinquish their binoculars instead. After long months of playing deadly games of cat and mouse, they recognized the German’s superior optics for the real threat and advantage they were.
The stakes for us hunters aren’t nearly so high, but the basic facts remain: optics are a critical tool in our pursuits, and top notch glass can mean the difference between a freezer full of meat and a pantry full of tag soup. But with the enormous array of options out there, strewn across a staggering price spectrum, how do you differentiate between the perfect pair and a waste of hard earned money? The $150 and $3000 pairs look an awful lot alike on paper after all.
Looking past the ad language and focusing on the key attributes below can help you make sense of the differences and find the right fit.
The Numbers that Matter – You’ve seen the specification charts. They’re very impressive, filled as they are with their row upon row of measurements, percentages and arithmetic symbols. Having acknowledged that, we can now feel free to ignore them. Most of what they list is in no way indicative of quality. The best 8 x 42 and the worst 8 x 42 pair of bino’s on the market will, for example, have identical field of view scores. A few of the specifications, like light transmission, will vary with quality, and are important. But without the context of an optical engineering degree, the numbers alone don’t help me much. It’s the performance that those numbers suggest that I’m interested in, and I’ll get at that another way.
The numbers that are critically important are the power and objective width. You see these in the top line product description typically written as power X objective, e.g. 8 X 42 or 12 X 50.
The first number, power, tells you the factor by which an observed object is magnified. Will it look 8 times bigger than with the naked eye or 12 times bigger? 8, 8.5, 10, and 12 are popular magnifications for most users, including hunters. At first blush, larger magnification seems like a universal advantage, but as magnification increases so does instability. At 12 power, most users will see a distinct image shake in most hand held situations.
The objective lens width, the number after the X, tells you how wide the lenses on the fat side of the binocular (the side pointed toward the object of observation, thus objective) are, measured in millimeters. The wider the lens the more light it collects and the brighter the resulting image. Size definitely has its advantages here. The primary trade-offs for larger objectives are bulk, weight and expense.
You can’t go wrong with powers from 8 to 11 when paired with objectives from 40 to 50. They are, by far, the most popular set-ups, and for good reason. Larger powers and objectives have a place too, and can be very impressive performers, but tend to favor specific conditions. Smaller models have the advantages of convenience and portability, but sacrifice some image quality.
Clarity – Clear – can I tell what I’m looking at? – is a baseline expectation. You can and should expect clear on the most entry level models. The best stuff though moves beyond clear, to deliver an image that is tack sharp, with no haze or fuzz whatsoever, and visual edges that are startling in their abruptness. Clear to tack sharp is a big performance leap. The next trick is delivering that sharpness from edge-to-edge. Most anyone can create a bino with good sharp images in the center of the field of view. It’s much more difficult, and requires the very best materials, to bring that level of clarity to the entire image. That may seem like splitting hairs, but it actually makes a big difference. If your eye is constantly straining to try and improve image quality, and/or is working to reconcile variable image quality, it wears out. Not only is eye strain uncomfortable, but it will keep you from using your specs as much as you need to, to find the game.
Light Transmission – Light is the name of the game. How much light a pair of binoculars collects is determined by the size of the objective lens. How much of that light makes it to your eyes is determined by material and design quality. The more light the better. Light transmission affects image quality at a fundamental level, but the wheat really gets separated from the light transmission chaff when it comes to low light performance. The difference in low light performance between a great binocular and a low-end model can be as much as fifteen minutes of functional observation time on each end of the day, maybe more. What’s it worth to you to add a half-hour onto the most productive times of your hunting day?
Eye Relief – You’ll find a measurement for this on the chart we’re ignoring, and it has a very specific definitions. I’m going to play it fast and loose with the definition here for simplicity’s sake. Effectively though, it determines the area where your eye must be, relative to the lenses, to see a full image unencumbered by vignetting or clipping – those annoying black arcs that cut into your field of view. Nothing is as annoying, distracting or damaging to effectiveness than vignetting. Do you have to hold the binoculars and your eyes just so to avoid it, or can you throw them up any old way and always see a full image? Good optics will have a generous and forgiving eye relief.
Focus –There are two elements of design that have a big bearing on keeping things in focus. First, depth of focus. Focus on a tree in the middle distance. Is the car twenty feet in front of it also in focus? How about the cow 40 feet behind it? As you’re typically taking in a lot of different terrain in a single glance, the larger range of distances that can be captured in focus at the same time the better. Play around with different models to figure out which excel at this. While you’re at it, pay close attention to the second element, the focus mechanism itself. How fast or slow is it to bring things into focus? Too fast and it can be tough to get it where you want it. Too slow and you’ll spend all day spinning the wheel. It’s a personal thing, like mouse speed preferences. Also personal is the feel of the mechanism. Is it too stiff, not stiff enough? Does it feel sturdy or chintzy? How well would it work with gloves?
Feel, Fit and Finish – Much like focus, these elements come down largely to personal preference, but they’re far from inconsequential. Are the eye-cups comfortable and adjustable to a setting that you’re likely to use? How heavy and bulky are they. Will they hold up to crawling over rocks and busting through the brush? Do the lens covers and strap work intuitively or are they difficult to adjust and always in the way? How easy it switch from strap to harness and back again? What if anything can I customize to fit how I’ll use them?
Hopefully these criteria help you evaluate your various options. There are still a few thousand to choose from though. Next week, with the last installment of our three-part STS binocular guide, we’ll try and narrow the field for you in time for the holiday gift buying season. Stayed tuned for our inaugural buying guide, and reviews of some of our favorites.