What the Numbers Mean
Binoculars have numbers, such as 8x30 or 10x40. The first digit is the magnification power, so if it has the number 8, that means the image you see is magnified eight times. The second number tells how bright the image will be, so a binocular with a rating of 8x40 will be sharper than one rated 8x25. The most commonly used binoculars for viewing wildlife are 8x40. It provides a balance between power, image quality and weight. The higher the magnification power, the more weight you will have to carry.
Choosing the Right Lens
Binoculars use multiple lenses, and every time light passes through one of them, the light--and brightness--of your image decreases. Different kinds of coatings affect how much light you see. Fully coated lenses have just one coat of chemicals that allow more light in. These are the least effective. Multicoated means some of the lenses have multiple coats of chemicals to allow more light, but not all. Fully multicoated is the best since every lens in the binocular has several coats of chemicals to allow the maximum amount of light to reach your eye. For bird-watching, fully multicoated is a must. You can get by with less coating and power for general wildlife viewing.
The Nikon Trailblazer ATB or Monarch, both 10X42, are effective for wildlife viewing. Prices range from $100 to $500, as of January 2010. Leica, another recognized camera company, also makes a line suited for viewing wildlife. Prices are between $200 and $800, as of January 2010. The Steiner 8x44 Peregrine XP is renowned in German optics, but carries a price of about $1,500, as of January 2010. Audubon is another popular brand, along with Bushnell, which sells suitable binoculars for about $200, as of January 2010.
There is a correlation between price and quality when buying binoculars. A higher-priced brand name often is more effective than a discount version. Find the balance you need, between power and image quality, as well as between weight and price. Try the binoculars before buying.