A guide to picking out binoculars

Buying binoculars can seem complicated, but it needn't be so. Most birders will find their needs and desires fitting comfortably in the middle ranges of function and price.

For information I turned to Kevin Smythe, optics buyer for National Camera Exchange. I have purchased several pairs of binoculars from Smythe, plus two spotting scopes.

I spoke with him because he understands my needs as a birder. I can deal face-to-face with him or other National Camera staff members. I can hold and try binoculars before I buy them. I could return the binoculars within 30 days if I change my mind. I trust the company.

There are other places to buy the same products. Just be certain that your salesperson understands your needs as a birder, not as a hunter or sports fan. Be certain that the binoculars you choose fit your needs — and your hands. (Put the strap around your neck. Let the binoculars hang. Feel their weight. Try the focusing mechanism to see how it works for you. Hold the binoculars to your eyes. Count to 15.)

Binoculars come in two shapes: Porro prism and roof prism. Porros have the traditional binocular shape: two boxy structures slightly ajar holding each set of lenses. Roof prism binoculars are straight and sleek.

We own four pairs of binoculars, all roof-prism: Leitz 7x35, Nikon 9x35, Swarovski 10x32 and Bausch & Lomb 8x42. (The latter pair has been well used for 30 years without problem.)

Smythe explains the numbers: "The first, the 8 in 8x42, indicates the power. The second number tells you the diameter of the front lens in millimeters.

"Porro prism binoculars provide better light transmission and better depth-of-field (more area in focus from front to back)," said Smythe.

"Due to their less complicated design, Porro prism binoculars are less expensive than similar roof-prism models. Roof-prism binoculars have grown in popularity among birders because they are significantly more durable, compact, and offer much better near focus," he said.

The most popular binoculars used by bird-watchers are 8x42's, Smythe said. "They provide a bright image, and are relatively easy for the average person to hold steady," he said.

Holding binoculars steady is important. "The largest drawback of higher power is that along with magnifying the object," he said, "it also magnifies the movement of your hands and body." This will cause the image you see to shake or appear jumpy.

He added that it is always a good idea to try holding a higher-power pair, to see how still the image is, before making a purchase. Actually, it's a good idea to hold and try any binocular before buying it. Find a window. Take a look. Don't be shy.

"While good quality Porro prism binoculars can be bought for $70-$120, the birding binoculars in the $200-$500 range are widely considered the best values," he said, "with $300 being the most popular price point."

Quality of the glass, waterproofing, physical durability, field of view, near focus, long eye-relief (ability to work well with eyeglasses), accurate color rendition and performance in low temperatures all add to a price, Smythe said.

"All the little things people find useful contribute to the cost of high-end models," he said.

"If you watch birds at your back-yard feeder from the comfort of your home, and rarely venture outside, save your money and buy a relatively affordable Porro prism model," Smythe said.

"The more you travel for birding, the more important become the features of a roof-prism model — durability, compactness and better near-focus," he said.

You can bird without binoculars. You can bird with big-box-store binoculars. Or you can bird with quality binoculars. The latter make an amazing difference.

Lifelong birder Jim Williams can be reached at woodduck38@gmail.com. Join his conversation about birds at www.startribune.com/wingnut.