Binoculars ( second )

1.  Make sure that the second number ("35" for a "7 X 35" pair of glasses) is at least five times as large as the power (e.g., "7 X 35," "8 X 40," etc.). This second number describes the diameter, in millimeters, of the large lens that faces the object of interest - the "objective" lens. The larger this lens is, the greater the amount of light the binoculars gather and thus the easier it will be to see characteristics in dim light or on a dull-colored bird.

2.  Are the binoculars too heavy for you to carry and use for at least two hours straight? Don't end up with a hunchback because your binoculars act like a yoke.

3.  Can you flex the barrels of the binoculars fairly easily? To test to see if they are too flexible, spread the barrels out as far as possible and then hold onto only one of the barrels. Does the free barrel slip or fall from the spread position? It shouldn't.

4.  When held a foot away, do the large objective lenses reflect a bluish or purplish tinge? If they do, the lenses are color-coated. This coating reduces internal glare in the binoculars and increases the amount of light that actually comes to your eyes. Check lenses to make sure the coatings are free of any blotches or scrapes.

5.  Can you bring the barrels of the binoculars close enough together so that the image you see merges into a single, clear image within a single, perfect circle? If the image isn't singular or clear, the binoculars may be out of alignment or the eyepieces may not come close enough together to accommodate your eyes. These two problems may lead to eye strain and severe headaches.

6.  Do you wear prescription eyeglasses? If you do, your binoculars should have rubber eye cups that fold back. This allows you to put your eyeglasses up closer to the eyepieces of your binoculars and gives you a much larger field of view.

7.  Do the binoculars produce a clear image of an object only 20 feet away? Some binoculars do not focus on objects this close, so you may miss the sparrow or warbler that skulks in a nearby bush.

8.  Look at a sign with large lettering. Do the letters close to the edge of the field of view appear as precise and well-formed as the letters in the center of the field of view? Image distortion towards the edge of binoculars is common in bad binoculars - like looking through a fish-eye lens. Look for a pair that has minimal distortion

9. When you focus on a license plate or small sign two blocks away, are the letters and numbers clear?  If they’re not, choose a different pair!

A general list of “don’ts” to consider when buying binoculars:

• Don't buy compact or pocket-sized binoculars (typically 8 x 21, or 10 x 21) as your primary pair for birding. The size and weight are attractive, but no matter how good the optics, compacts provide a lower quality image than mid- or full-size binoculars. Another drawback is that most compacts have a narrow field of view, which makes it very difficult to locate and follow birds.
• Don't buy zoom binoculars. Expert birders report them as being inferior.
• Don't seek advice on buying optics from non-birders. Hikers, hunters, and boaters have different needs than birders. Looking at birds is not the same as looking at other wildlife. Pocket binoculars are fine for looking across a savannah at an elephant or a cheetah, but they are not suitable for birding. Marine binoculars provide a sharp, bright image, but are too big and heavy to carry around all day.
• Don't buy binoculars until you have tried them. Make sure they feel comfortable in your hands. Look through them and be sure you get a clear, unobstructed view. Different models suit different people, and each instrument varies. If ordering by mail or online, make sure that you can exchange them.

One thing about binoculars – you don’t always have to have the best specs for bird watching.  Any binoculars are better than none at all.  The thing to remember is that you need to have something to magnify the birds you will be looking for.  If you are serious about bird watching, take heed of the tips for buying binoculars given above.  They will be well worth the money!