High Power Binoculars - A Few Questions Answered

What do the numbers on high power binoculars mean?

The first number indicates the magnification level of the binoculars. A "10x50" for example, means that the view is magnified 10 times. Anything viewed through them will appear 10 times larger than without the binoculars.
The other number indicates the objective size (diameter) in millimeters. The large lenses at the end of the binoculars (opposite where the eyes go) are the objectives. The size of the objectives determines how much light-gathering power the binoculars will have. For the most part, larger objectives make for a bigger image, but the physical size and weight of the binoculars increases as well. Those with large objectives will tend to have a price to match.

How powerful of binoculars can I hand hold?

This depends greatly on the individual, and involves magnification and size. It also depends on the intended usage - daylight viewing or astronomy? For astronomy, the most magnification that can reasonably be hand-held is around 12x. Go any higher and the image will be too "shaky" to get a clear view. For viewing in daylight, magnifications higher than 12x can be hand-held because the shaking has a lesser effect.

The second factor is weight. Binoculars over 4 pounds are going to be quite the handful to use without a tripod for most people. It won't take long at all for the arm muscles to get tired out. Especially for extended use, keeping the binoculars under 3 pounds will make for the best experience.

How important is quality in high power binoculars?

The higher the power of the binoculars one is using, the more important the component quality is. As they get more powerful, any flaws or deficiencies in the lenses or prisms will become more noticeable. When springing for the increased cost of powerful binoculars, it's worth the additional investment to aim for top quality.

Many factors affect the quality and price of a premium pair of binoculars. These include optical considerations like the type of glass used for the lenses and prisms, the eyepiece design, the type and size of the prisms, care taken in grinding and polishing the glass elements, and the type and coverage of anti-reflection coatings. There are also mechanical considerations. These include the material of the lens barrels, the construction of the lens barrels (whether they are one or two piece), the mounting and retainment strategies used on the lenses and prisms, the focusing mechanism, and the finish of the outside of the binoculars.