Selecting the best optics, by the numbers


The spring migration of birds is a good time to buy or upgrade binoculars. That’s why I wrote a brief primer on binoculars about a year ago. I explained, for example, that every pair of binocular is described by two numbers, which are usually found on the center focus wheel.

For example, 8×42 and 10×42 describe popular birding binoculars. The first number indicates the magnifying ability of the lenses. Eight power makes things appear eight times closer; ten power lenses bring things ten times closer. Higher magnification requires steadier hands.

I have both eight and ten power binoculars, and I use eights most of the time. Avoid anything stronger than 10-power because they are just too difficult to hold without shaking.


The second number is the diameter of the objective lenses (the ones farther from your eyes) in millimeters. The larger this number, the more light the lenses transmit and the brighter the image will be. Brighter is better, especially for early morning birding, but bigger objective lenses mean more glass.

And that means more weight. Another consideration that many people don’t understand until after they’ve made a purchase is that binoculars must “fit,” just like a pair of glasses or gloves. Even expensive binoculars will frustrate users if they are too big or small for their hands or if they can’t be adjusted to fit the distance between their eyes.

If you buy online, be sure you can return them if they don’t fit. Also be sure any new binoculars you buy are waterproof and guaranteed for life, both good signs of quality. This simply protects your investment.

Weight is also an important factor that many users don’t think about until after they’ve purchased their binoculars. Bigger binoculars typically provide a brighter view, more magnification and more weight.


A solution to heavy binoculars is to wear them on a harness rather than a neck strap. For all-day comfort, a harness, which costs about $20, distributes the weight of the binoculars across your back and shoulders rather than around your neck.

Finally, be aware of how close binoculars focus. Though most birding is done at a distance, sometimes birds are surprisingly bold, and the ability to focus closely enables incredible details to be observed.

Plus, if binoculars can focus down to 5 or 6 feet, they are perfect for studying butterflies, dragonflies, wildflowers, and snakes. Though many readers have let me know they appreciate the basic information I just described, they want more.

I regularly hear from readers who want specific recommendations. “Tell me exactly what to buy,” they say.

I’m reluctant to give specific recommendations because everyone’s precise needs are different. Plus most manufacturers offer excellent binoculars. It’s hard to go wrong with brands such as Bushnell, Eagle Optics, Kowa, Leica, Nikon, Steiner, Swarovski, Swift, and Zeiss.

What I use

Rather than recommend a specific brand and model of binocular, let me just tell you what I use. My best (most expensive) binoculars are full-sized 8×42 Bushnell Elites (25.7 oz.). They retail for $728.95, but can be had for $459.99 at

My favorite binoculars (the ones I use most and keep in my car) are 8×32 Eagle Optics Rangers (19.2 oz., $389/$290). Eagle Optics also makes Rangers with better quality glass, the 8×32 Ranger ED (19.8 oz., $539.99/$439.99) and 10×32 Ranger ED (19.6 oz., $549.99/$449.99).

And recently I’ve come across several more binoculars I really like. Eagle Optics’ 8×42 Shrikes (23.2 oz., $149/$99.99) are perfect for beginning birders and first time buyers. For a step up in quality, consider Bushnell’s Legend Ultra HD 10×36 (20.6 oz, $379.50/$249.95) and Steiner’s new Merlin Pro 10x32s (22 oz., $449.99).

I prefer more compact, lightweight binoculars for every day use. But don’t blindly follow my recommendations. Shop around, and be sure new binoculars fit your eyes and hands. For more information about optics, visit

Eagle Optics also sells many brands of optics at discounted prices. And their customer service is excellent. Another source of great information on optics is BirdWatcher’s Digest’s web site ( Click on “Optics and Gear” for reviews and recommendations by optics experts Michael and Diane Porter.

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  1. Bushnell has been a household name for binoculars since I was a kid, about 40 years ago. My dad bought one and to this day it works as good as new. Great quality.


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