Don’t give binoculars as a gift this holiday season. Instead, give yourself a better pair. Optical equipment is very much a matter of personal taste. One size does not fit all and, frankly, some don’t fit anybody. Try many different pairs until you find exactly the right pair for you.
Start by asking to try those of your fellow birders. Then, visit a birding store, or several, and try them all out. The Fields Pond Audubon Center in Holden has a nice selection, but no store carries every brand.
Ask for advice, and listen. You need to get the basics right, but you also need to make the right tradeoffs. There are no perfect binoculars. Every pair is a compromise.
Binoculars are described by a pair of numbers, such as 10×50. The first number is the magnification or power. A pair of 10-power binoculars makes an object appear 10 times closer than it really is. That’s where the compromising begins. The 10-power binoculars magnify more than 7s and 8s, but they’re heavier, harder to hold steady, often reduce the field of view, and may not let you get as close to that mystery sparrow under the bush. Experienced birders often select a lower magnification in order to avoid these negatives. If you can identify a bird at 10-power, you can usually do it at 8-power. But not always.
In order to make the object appear bright enough, the front lenses (the objectives), need to gather additional light. The second number describes the size of the objective lenses in millimeters. A 10×50 pair of binoculars uses 50-millimeter objectives to magnify 10-fold.
Objective size is also a compromise. The old wisdom was that you wanted the second number to be five times larger than the first for optimal light-gathering. Any more than that and the beam of light would be wider than your iris could accommodate, thus adding weight without benefit. Popular sizes were 7×35, 8×40, and 10×50. Binoculars that cheated on the 5-1 ratio might be fine on a sunny day, but frustrating in low-light conditions, such as at dawn when the warblers are active and your 10×25 binoculars are useless.
Recent technological advances allow some cheating without a loss of brightness. They use new materials and coatings that reduce the amount of light that is lost through diffusion or reflection. The trade-off is that these binoculars are more expensive. You should always try out binoculars in low-light conditions.
Even cheap binoculars perform well in bright sunlight. My advice is to pick a truly miserable day in order to go visit birding stores and comparison-shop. Binoculars come in two basic styles. Porro prism binoculars are the style you likely grew up with. On most, the front lenses are set wider apart than the eyepieces. (Some models set them closer together.)
They are focused by moving the eyepieces forward or back. You can see the movement. Roof prism binoculars feature straight barrels and the moving parts are internal. In the old days, roof prism binoculars were more sturdy and waterproof, but did not pass as much light. Nowadays, technical improvements have allowed roof prisms to narrow the brightness gap, even in less expensive models. As a result, durable roof prisms have become much more popular.
The trade-off between budget-friendly and high-priced binoculars is the most complex. For decades, quality binoculars were produced by just a few American, German, and Japanese manufacturers. Lately, the British and Chinese have stepped up the competition. With the increased popularity of birding, there is now greater demand for good optics. Competition hasn’t lowered the price of high end binoculars very much, but it has vastly increased the range of choices at moderate expense. Many $300 binoculars deliver quality that used to cost twice as much.
Since many binoculars deliver images of comparable quality, your choice may be driven more by comfort. Compare the weight, the grip, and the ease of focusing. The size of your hands may determine whether the binoculars are easy to hold and the focus mechanism simple to use. Try holding and focusing with one hand, which I find myself doing whenever I’ve also got a scope on my shoulder.
Your budget may not let you get carried away, but remember: you’re likely to own your new binoculars for a long, long time. My own high-end binoculars cost me just pennies on a per-use basis and I can see that twilight merlin on the distant treetop.
Bob Duchesne serves as a Maine Audubon trustee and vice president of its Penobscot Valley Chapter. Bob developed the Maine Birding Trail, with information at www.mainebirdingtrail.com. Bob can be reached at firstname.lastname@example.org.