It is a monumental decision in the life of any birdwatcher. At stake is nothing less than the pleasure you get in the company of birds. So here is some advice on buying and using binoculars.
First, recognize that bigger isn’t always better. Binoculars bear two numbers: 7x35, 8x30, or 10x50, for example. The first is magnification. You’re fine with 7- or 8-power. Sure, a power of 10 makes the tanager appear even larger, but it also magnifies your own trembling (and who doesn’t tremble in the presence of a tanager?). Higher magnification also reduces your field of view – the breadth of habitat you see out there. Say you spot a bird and lift your binoculars for a look … and can’t find it anywhere. If this is all too familiar, your optics might be too powerful (or your aim needs practice). I bird with a pair of 8x42s.
The second number is the diameter of the objective lens (the bigger end) in millimeters. A larger lens gathers more light and therefore improves the view, but it also adds weight and bulk around your neck. There is little reason to go larger than 42 (or smaller than 30).
Which brings me to compact binoculars. Avoid them. They’ll likely have an objective lens around 20mm, so the view is dark and dingy. And compacts are nearly impossible to use while wearing gloves or mittens during winter birding. Their only reason for existing might be as a spare pair in the glove compartment. I backpack with mid-sized 8x30s.
Next, beware of unruly eye-cups. We used to nestle our eyes into rubber eye-cups. Birders wearing eyeglasses would fold the eye-cups down to position their eyes the proper distance from the lenses. Modern eye-cups twist out to various positions, an innovation that has ruined some fine binoculars. Poorly designed eye-cups can twist out of position on their own. So, when shopping, be sure the eye-cups snap and lock in place – all the way down, all the way out, and at one or more points in between.
Test drive binoculars in lousy light – not bright sunshine, where most binoculars will perform well. Avoid gimmicks such as zoom lenses, built-in cameras, and models with technology to stabilize hand trembling. Make sure your binoculars can focus on objects as near as six feet, because at some highly evolved point in your birding career you will discover the pleasure of watching insects, and you will curse your binoculars if you must back away from a dragonfly to get it in focus.
Even if you’re standing by your old clunkers, learn the diopter correction. It allows you to adjust your binoculars for the natural variation between your two eyes. The correction is easy to perform but varies by model. If it’s not right, everything you view will be out of focus. Once you’ve made the correction, however, your binoculars are likely to be out of focus for the person who shares them with you.
Dirt, pollen, fingerprints, egg salad, coffee, and worse will inevitably find your optics. The critical advice here (besides investing in lens solution and cleaning paper or a lens cloth) is to buy a lens brush. Always brush away grit before you start rubbing your lenses to clean them. And always rub gently.
Finally, after you do careful research, spend as much as you can. Some fine binoculars can be had for $200. But true birding bliss comes at a price – a scary price. If birding is big in your life, spend the money and spread the costs well into your bright future, which can be 15 years or more if you choose well and take good care of your investment. After all, out there in the hardwoods, you don’t often get an unobstructed view of a scarlet tanager. So make every view count.
Bryan Pfeiffer is an author, wildlife photographer, guide, and consulting naturalist who specializes in birds and insects. He lives in Montpelier, Vermont.