Thus, a prism that indicate his mount 8 x 40 means is 8X, and the diameter of the front lens is 40 mm. POWER The power of the prism, that is, the increase is a factor of great importance, and indicates the ability to zoom binoculars. As noted, the increasing value is indicated by the first digit of the pair registered in the saddle. Values increase under 8 must be regarded as low, being equally low prismatic capacity to zoom in and see details. Values between 8 and 10 are normal, and identify binoculars for general use, adaptable to a wide range of requirements (boating, hunting, nature, surveillance, etc.).. Values increase from 10 to 16 are decidedly higher, and achieve a notable about the image, with great capacity for appreciation of detail. Finally, binoculars increases above 16 are very powerful, being especially suitable for specialized applications (long-distance observation, astronomy, etc.)..
The increase in power binoculars usually involves a greater tendency to shake the image. Thus, an untrained person can focus easily by hand 8x binoculars, while with 16X binoculars will most likely find an unpleasant vibration of the image, having to resort to the aid of a tripod. In general, prismatic increase above 12 suggests the use of the tripod, and is almost bound (if you want an accurate picture) in 16X binoculars or higher. As a notable exception, are on the market some high-magnification binoculars mechanically or electronically stabilized (ZEISS, NIKON), they do not need a tripod, although at very high prices accordingly.