For Beginners
A sharply focused pair of binoculars will do more to increase your enjoyment of bird watching than anything else. Changing lighting and distance and tough fieldmarks make great optics a necessity for the serious birder.
Full-size objective lenses (35 to 50mm in diameter) allow for bright images at twilight and on overcast days in thick cover. Many bird watchers prefer seven (7x) or eight power (8x) binoculars. Binoculars at these powers are easier to hold steady, resulting in more pleasant birding.
As you consider how and where you will be birding, also consider stability and ease of use. When durability is important, realize that a more durable construction adds to the cost of the binoculars.
For the beginner bird watcher or the backyard enthusiast, binoculars priced in the $100 to $300 range should be more than adequate.
Consider the following sizes and powers that work well for most bird watchers.
7x35, 7x42:
Excellent brightness and close-focusing. Also offers a wide field of view
8x40, 8x42, 8x43, 8x44:
A nice compromise of brightness and power.
10x40, 10x42:
High-powered optics for long distance birding and excellent magnification of the subject.