The Essential Optic

Bino-truism: More Magnification Isn’t Always Better
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Distant glassing accounts for most binocular use. Thus, the trend to higher power, bigger objectives.

Sight is a wonderful gift. To see is to discover. Sight also confirms — and helps us achieve. Vini, vidi, vici: “We came, we saw, we conquered.” Sight is power.

Our eyes need light to see. Light has properties of particles and rays. As early as A.D. 1100 Arab scientist Alhazen described the behavior of reflected light. Egyptian geographer Ptolemy followed with observations on refraction. In 1621 Dutch spectacle-maker Willebrord Snell showed every substance has a refractive index. By then, Italian astronomer Galileo Galilei had built a telescope with convex front (objective) and concave rear (ocular) lenses. But Johannes Kepler upstaged Galileo by bringing the focal point inside the telescope from behind the rear lens.

If these men could see Walmart’s optics selection today, they’d be stunned.

See best with a two-hand hold — braced when possible. Don’t pan. Choose modest magnification.

On The Ground

The telescope sired the spotting scope. When it was realized people had two eyes, the binocular was born — essentially two short telescopes joined by a hinge.

Years ago, hunting with the Inuits above the Arctic Circle, I carried a Bausch & Lomb 7x35 Zephyr, a wonderful binocular for its day. The patriarch of our group, a leathery man with hair pale as moonlight on snow, had a cheap, battered 7x50. He held it vertically, squinting through the bottom barrel because the other didn’t work. After canoeing through rowdy seas along the northern reach of Hudson’s Bay, we pitched tents on a rock spit. During the night, a south wind jammed a mountain range of ice against our shore. We hunted caribou the next day. The old man with the one-eyed binocular staggered in after dark with six hides strapped to his back by a rope. He’d shot all the animals with an iron-sighted .22.

Limited to one hunting optic, I’d pick a binocular over a riflescope. Indeed, my last hunts have been with open sights. A scope extends effective shooting range; it won’t help you find animals.

A binocular can help most up close, where you must see game before it spots you, where you’ve no chance for a second look. Once, cresting a ridge, I immediately set to with my binoculars, picking apart a distant meadow. Then a twig snapped. Scant yards below me, a bull elk strolled into cover. He’d been there all along. I’d lost my chance by looking first where glassing was easy, instead of using the bino where glassing was urgent.

Another time, traipsing through African thorn, my binocular dangling, I all but bumped against a rhinoceros. He could have left footprints on my khakis but evidently he decided anyone blind to a beast the size of a sedan at a few feet was harmless.

Bill McRae worked as an optics consultant for Bushnell. “I miss binoculars like this,” he told me once, hoisting an aged 6x30 Bausch & Lomb. He saw the glint in my eye. “It’s not for sale.” While the 6x30 and my 7x35 Zephyr can’t match current glass optically, they’re lighter than the 8x42 and 10x42 binos so popular now. No need for a harness you’ll have to fight with while shedding your jacket — and whose elastic soon weakens so the bino bounces on your chest and drags in sand and snow when you crawl.

This cutaway of a Swarovski binocular shows its complexity. Good glass is costly for a reason!

You need binos that yield bright images to the end of legal shooting.

More Power, Less Versatility

Like riflescopes, binoculars have grown more powerful and, arguably, less versatile. A 6X bino makes a deer a quarter mile away appear as big as a deer looks to the naked eye at 73 yards. Though more power delivers more detail — and has a place in big mountain basins — the wide field of a 6 or 7X lets you see more without moving the bino. It also yields a deeper field-of-view; the range of acceptable focus is greater, both closer and beyond the range you’ve chosen for tack-sharp focus.

If you’re a still-hunter, you’ll often glass without support, sometimes pausing in a climb. Magnified, your pulse bounces the image. Low power quells the quake — and delivers big exit pupils (EP) with small front glass. An EP of 5mm seems to me big enough for all but bat-cave conditions. You get it with 30mm objectives in a 6X binocular, 35mm lenses in a 7X. You need 50mm glass to snare 5mm EPs in 10X binos. Weight and bulk stack quickly.

I favor porro-prism (offset) barrels to the ubiquitous roof-prism. They’re easier to hold and the bigger the gap between front lenses, the greater the binocular effect helping you judge distance. Try ranging an animal with one eye closed!

As gnashing my teeth over the demise of low-power porro-prism models hasn’t revived them, I’m inching closer to trim roof-prisms. Binoculars heavier than 20 oz. become a burden on the single strap I keep short to limit swing and permit a quick tuck for a crawl. Meopta’s MeoPro 6.5x32 is a champ. I also like the 8x32 Zeiss, Leica’s 8x32 Ultravid BR, Swarovski’s 8x32 EL. All are around 20 oz. All are expensive and worth their street price.

Fortunately, you don’t have to pilfer your child’s college fund because mid-price binos are now very good. Check them for fully multi-coated lenses and needle-sharp resolution. Check the spin of center and diopter adjustments, along with the comfort of the eyecups. Peer into shadow and sunshine. Beware field curvature, color fringing. Zeiss’s LotuTec, Bushnell’s RainGuard and other water-shedding treatments clear the view in wet weather.

Remember: Every hunt hinges on what you see. Galileo didn’t buy cheap glass.

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