Binoculars are one of the handiest, useful and most widespread of all optical instruments. Virtually everyone who spends time outdoors owns, or needs to own a pair of binoculars. More than 46 million birdwatchers spend almost $500 million annually on binoculars and related equipment in the U.S., according to the federal Fish and Wildlife Service. Birdwatchers aren't the only ones looking to get close to their subjectsboaters, hunters, sports fans, theater-goers, and experienced travelers all rely on binoculars.
But binoculars are about more than simple magnification or power. Depending on how you plan to use them, you'll want to think about varying combinations of weight, power, image quality, durability, field of view, and ease of use.
The first thing to understand about binoculars is that they are really just two small telescopes mechanically linked together. All of the facts and information that help you to understand telescopes also pertains to binoculars. Each side of a pair of binoculars has a prime focal length, an objective lens (front lens), an ocular (eyepiece lens), and an exit pupil.
Price is a factor. But surprisingly, in recent years tests have shown that quality doesn't always come with price. More-expensive models do have more-effective coatings on their optics (lenses and prisms), which sharpen the image and keep stray light from bouncing around inside the binoculars. These coatings assist light transmission. They are what produce the blue, red, or green reflections you see when you look into the front objective lens of a pair of binoculars.
Overall, the lens and prism quality have been much improved in binoculars these past few years. However, the biggest innovations or changes in binoculars over the last several years have been in the addition of image-stability technologies and digital-camera capabilities. A product that is well made of high quality components is for the best overall good, and it is always worth the extra money over shoddy popular priced binoculars. Quality control costs the manufacturer, and you, money, but it is worth it because the result is a better performing pair of binoculars that can last a lifetime.
Many things affect both the quality and the price of a pair of binoculars. Choose yours by considering the best for your particular needs in hunting, bird watching, sports, or nature viewing.