Do You Need a Pocket Binocular?

Do You Need a Pocket Binocular?

By Clair Rees

Quality full-sized binoculars aren’t the best choice for all hunting situations.

I first began hunting as a cash-poor teenager who could barely afford a knife and a box of ammo. The Arisaka rifle I carried was on loan from my favorite uncle. My young eyes were sharp, so buying a binocular never even crossed my mind.

A few years later, a more experienced hunter convinced me I needed a decent binocular. “Your rifle is useless until you’ve located and stalked your game,” he said. “The binocular helps you do this. It’s an invaluable tool that will make you a more successful hunter.”

I bought a cheap secondhand binocular, but it proved worse than useless. It produced instant headaches, and I soon threw it in the trash. It was also too heavy and bulky for easy carrying.

Looking for a more compact solution, I settled on a 6x26 Custom Compact binocular from Bausch & Lomb. It tucked away in a shirt pocket and produced a bright, clear viewing picture. I didn’t know a lot about optics then, but I learned that because of its optical quality and compact size, this reverse porro prism binocular had been chosen to accompany the Apollo astronauts to the moon. That was good enough for me.

I happily used that little binocular until I hunted Alaska’s giant grizzlies with Ed Stevenson as my guide. When it wasn’t snowing or raining, the November sky remained darkly overcast. Late one afternoon, Ed pointed out a large boar he’d spotted walking along the far side of Gravina Bay. He could see it clearly through his 10x40mm Zeiss binocular, but my little Bausch & Lomb wasn’t up to the task. I could see the bear’s bulk, but the image was too dim to show any detail. In those conditions, the 26mm objective lenses simply didn’t transmit enough light. The Zeiss optics were clearly superior for this kind of hunting.

I bought a good full-sized 10x40mm binocular soon after returning home. The 6x26mm B&L was relegated to waterfowl and pheasant hunting duties, where high magnification wasn’t required. I didn’t want a bulky, heavy binocular hanging from my neck when toting a shotgun, and I barely knew the Custom Compact was in my shirt pocket. It was invaluable for checking large fields for pheasants, or for spotting flights of geese before they winged into range.

I’ve since used a variety of 8x, 10x, 12x and even 15x binoculars featuring 32 through 60mm objective lenses. I’ve found standard 8x or 10x binoculars ideal for all-around hunting. Quality full-sized binoculars can be used for several minutes — even hours — at a time without causing eyestrain or other discomfort. They’re the ideal tools for finding and evaluating trophy game, then identifying a likely stalking route. If you own only one binocular, make it a full-sized 8x or 10x model with a 40mm or 42mm objective.

While I’m sold on quality full-sized binoculars, they’re not the best choice for all situations. When weight and bulk are at a premium, compact binoculars are worth their weight in hummingbird feathers.

I once backpacked into Utah’s Uinta Mountains with my friend Del. We were looking for high-country deer. This would be a solo five- or six-day hunt, which meant lugging everything needed for warmth and sustenance on our backs. This included a lightweight two-man tent, a backpacking stove, cooking and eating utensils, sleeping bag and pad, first aid kit, extra underwear and a change of clothing, flashlight, water purification kit, and food for the entire trip. Add a scoped rifle and backpack for each of us, and we had all the heft we were willing to carry.

Do You Need a Pocket Binocular?Realizing the effort it would take to get freshly killed venison down the mountain, we agreed we’d shoot only one deer. Whoever had the first shot would take it.

My full-sized 10x40mm binocular weighed nearly 2 pounds, while Del carried a tiny 10-ounce 10x26mm binocular in his shirt pocket. I kidded him about his “toy” until I compared its performance to that of the considerably larger, heftier glass hanging from my neck. In the cloudless, sunny conditions we encountered, the little 10x26 binocular delivered a surprisingly bright, sharp image. It more than held its own with the far bulkier and heavier glass I carried. Considering its featherlight weight and compact size, it was a fine choice when every ounce packed up the mountain counted.

While the type and quality of lens coatings play a big part, along with the quality of internal prisms and optical glass, light transmission (and image brightness) is largely determined by magnification and the diameter of the objective lenses. Dividing objective lens diameter by magnification tells you the size of the “exit pupil.” You can actually measure exit pupil diameter by holding the binocular at arms length and pointing it at a source of light. The small circle of light you’ll see in the eyepiece — the exit pupil — can be measured with a ruler.

In dim viewing conditions, the human eye can accommodate all the light a 7mm exit pupil passes on. Any additional light is wasted. That’s why some binoculars — particularly those made in Germany — feature 8x magnification and huge 56mm objectives. Germans often hunt in virtual darkness, which they call “prime hunting light.” Dividing 56mm by 8x gives you a 7mm exit pupil — the optimal size for late-evening or early-morning viewing.

In normal daylight, a 7mm exit pupil is unnecessary. In good light, a 4mm exit pupil does the job nicely — think 10x40mm or 8x32mm binoculars. Even 3mm isn’t bad. The 6x26mm Bausch & Lomb Custom Compact I first owned provided a 4.3mm exit pupil, which was more than adequate for daytime viewing. The latest version of this pocket binocular is the 7x26mm Bushnell Elite Compact. Exit pupil size is 3.7mm, which transmits slightly less light than the original 6x26mm B&L did, but still provides good viewing.

Two other shirt-pocket binoculars I’ve recently been using include Steiner’s roof prism 8.5x26mm Wildlife Pro, which delivers a 3mm exit pupil, and a Minox BV 8x25mm Minx BRW, with its 3.13mm exit pupil. In normal daylight, these binoculars provide a surprisingly sharp image, yet they weigh only 10 ounces or so and fit handily inside a shirt pocket. All three of the compact binoculars just mentioned can be purchased for less than $300 (the 8x25mm Minox lists for just $149).

I prefer 7x or 8x minis to the 10x models most manufacturers also offer. While you get greater magnification, a 10x25mm binocular delivers an exit pupil just 2.5mm in diameter. The smaller the exit pupil, the less light the binocular transmits.

I don’t use these handy little binoculars exclusively for hunting. Whenever I’m hiking through the woods or simply camping, one of them always rides along in my pocket. A few years ago, I climbed Mt. Timpanogos, an 11,600-foot-high mountain not far from my front door. It was an 18-mile round-trip climb, and I didn’t want to carry any excess weight. The shirt pocket binocular I took along allowed me to watch the antics of mountain goats and scan the valley below while resting at the summit. I wouldn’t have traded it for any of the heavier high-end binoculars I own.

This article was published in the August 2008 edition of Buckmasters GunHunter Magazine. Subscribe today to have GunHunter delivered to your home.

Copyright 2018 by Buckmasters, Ltd.

Copyright 2017 by Buckmasters, Ltd