Biology Reference
In-Depth Information
pull up your glasses to view it. It can be frustrating at first, but once you master finding
inanimate objects and resting birds, finding moving birds through your binoculars will
soon become second nature.
The largest Red-tailed Hawks weigh three pounds. A dog about the size of a red-tail
would weigh at least 10 times that!
BUY THE BEST BINOCULARS YOU CAN
There are hundreds of kinds of binoculars, and almost as many opinions about how to
choose them as there are birders. The trick is to find the ones that are best for you and
your budget, keeping in mind six key features of binoculars: prism type, magnification,
brightness, field-of-view, comfort, and price.
Types of Binoculars
Therearetwobasicbinoculartypes:roofprismsandporroprisms.Thereisonemoremir-
ror inside roof prisms, which means the view is slightly dimmer, which is a serious con-
sideration when you're buying on a budget. For the same price and manufacturer, porro-
prisms give a slightly better image. That said, the design of porroprisms makes it easi-
er for dirt and grit to get inside the binoculars, and they're harder to waterproof. Most
top-of-the line binoculars are roof prisms because they are so much easier to keep clean.
Avoid choosing binoculars that have separate focus adjustments for each barrel — these
are a very poor choice for birding, when you need to locate the bird and focus quickly.
Magnification and Brightness
Every pair of binoculars is described with two numbers, such as 8×40, 10×50, or 6×32.
Thefirstnumberisthemagnificationandthesecondnumbertellsyou,inmillimeters,the
diameter of the objective lens, which affects the brightness of the image. The magnifica-
tion number tells you how much closer objects appear through the binoculars. Ten-power
glasses bring things ten times closer. For otherwise identical binoculars, the higher the
power,thecloserthebirdappears.Thereisatrade-off:theimagewillappeardimmerand
