Birdwatching, or "birding" is one of the most popular hobbies to enjoy outdoors. Millions of people all over the world participate in some form of birding. One of the main reasons for birding's popularity is that it's inexpensive - all you need is a field guide or birding app for your smartphone and a good pair of binoculars. Whether you're a dedicated birdwatcher or you just like seeing what shows up at the backyard feeder, the most vital tool for appreciating the natural beauty of birds is a binocular optimized for daytime use.
So what makes a binocular good for birding?
Quality optics, for starters. Image sharpness and brightness are vital for a pleasing birdwatching experience. Anti-reflection coatings on binocular optical elements help to maximize the amount of light that passes through a binocular. Binoculars with quality, fully coated, or better yet "fully multicoated optics" are ideal for bright, sharp views, since they allow a maximum amount of light to be transmitted through the binocular to reach your eyes.
Another important factor to consider when comparing binoculars for birding is power, or magnification. While it's tempting to assume that more power is always better, it's just not true. Binoculars with magnifying power of 7x or 8x are arguably the best for all-around birding. Such moderate magnifications make it easy to hold binoculars steady for stable, shake-free observations and usually provide a wider field of view to explore. While more powerful 10x or higher binoculars may come in handy for viewing over longer distances, they are more difficult to hold steady and usually also have a narrower field of view.
You should also pay special attention to the size of a binocular's front lenses (also called "objective lenses") when shopping for a good birdwatching binocular. Objective lenses (the front lenses of a binocular) measuring 35mm to 42mm in diameter are preferred for birding binoculars, and many quality compact models with 26mm lenses also perform admirably during the day. You don't really need larger lenses unless most of your observations will occur at dawn or dusk. Binoculars with 42mm lenses gather ample light for bright, clear daytime views of birds and wildlife. Binoculars with 42mm and smaller objective lenses are usually more portable and compact than binos with larger lenses, and you'll appreciate their relatively smaller sizes when you take a birding binocular along with you on a hike, camping trip, or birdwatching expedition.
Another specification to be aware of is a binocular's close focus or near focus distance. This defines how close you can be to an object while obtaining a focusable view in the binocular. A short close-focus distance of 10 to 20 feet or less is a plus for studying birds at close range.