What do the numbers on high power binoculars mean?
The first number indicates the magnification level of the binoculars. A “10×50” 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 “
