What are the considering issues to choose a birding binocular

Binoculars are suitable for several different activities:  hiking, star gazing, fishing and bird watching.  All types of binoculars work basically in the same manner.  Light enters, is magnified, flipped over, and then exits to your eyes (image).  Binoculars focus by moving one or more lenses so objects can be seen at a distance or up close.  Binocular images are brighter, detailed and more three-dimensional than those seen with the naked eye, making them the perfect device for seeing birds up close. 

Birding "professionals" will tell you that the best birding binoculars are ones that are compact, yet large enough to gather a good amount of light.  Focus and a wide field of view are two important considerations when looking at binoculars.  Fixed focus binoculars won't function well at close distances and should be avoided for bird watching.  

Separately focusing eyepieces don't react quickly enough to capture bird images, so they should also be avoided.  A wide field of vision will enable the bird watcher to track the path of a flying bird.  A stabilized image view is important as well since birds are constantly moving. 

Overall, birders need binoculars that are lightweight, focus quickly, work well in dim light conditions, and feel good when held in their hands.  It's also important to consider the conditions in which you'll be viewing birds.  Rain, moisture, dust and salt spray (ocean environments) must not be allowed to enter your binoculars, or they'll be ruined. 

A favorite among experienced birders is the Leica Ultravid HD Binocular.  The price range is on the high side, ranging from $1,700 to over $2,000. 

The features of this type of binocular are as follows: 

1. Aqua-Dura coating - this coating is used on the external glass surfaces and allows water droplets on the lenses to drip cleanly away, so vision is clear even when it is raining.
2. Manufactured using special types of fluorite glass - used in lens elements which ensures a brilliant, sharp image.
3. Excellent contrast right to the edge of the imgae
4. No color fringing
5. Improved prism coating technology - 3% increase in overall light transmission.
6. The focusing feature works effortlessly, even in extreme temperatures. 

Recommendations by experienced birders include, at the top end, birding binoculars manufactured by Leica, Swarovski, Minolta, Steiner, Zhumell, Nikon, Zeiss, and Bausch & Lomb.  For brands and styles under $500, consider Pentax, Celestron, Eagle Optics, Nikon, Swift and Audubon.  For those just beginning and for whom budget is a concern, value-priced, but good quality birding binocular models can be found through Nikon, Celestron and Bushnell.  

The best birding binoculars are different for everyone, so conducting research on each brand and design is good place to begin.  Other considerations are quality construction and optics and manufacturer support.  Talk to experienced birders about their preferences and which ones have worked well for them.  Try some out yourself, either at a local dealer or from an online retailer.  If you do order binoculars online, make sure the dealer has an acceptable return policy in the case the binoculars aren't a good fit for you.