A binocular is a device in which two identical telescopes are mounted side by side, aligned to point exactly in the same direction allowing the users to view distant objects using both eyes. Binocular telescope are also commonly known as field glasses. Most of the binocular telescopes used at the present time are sized to be held using both hands. A binocular telescope unlike a monocular telescope offers users a three dimensional image. Both views presented from slightly different viewpoints generate a merged view so with the help of binocular there is no need to close one eye in order to avoid confusion.

Different types of binoculars are used for different purposes, a small hand held binocular range from small 3 x 10 Galilean opera glasses are commonly used in theaters, most of the binocular telescopes available nowadays are designed for outdoor use. Like most of the hunters and bird watchers use most expensive binoculars that are very light in weight. You may also have seen a number of tourist attractions have installed pedestal mounted binocular telescopes in order to allow the tourists to obtain a clear and closer view of the attraction. Different types of binocular telescopes are also commonly used for military purposes. Galilean binocular telescope designs were widely used till the end of 19th century. Binoculars designed for military use are very different from ordinary binoculars, military binocular telescopes normally avoid more fragile center focus arrangements in favor of independence focus. Prism sets in binoculars designed for military use also have redundant aluminized coating on the prism sets to assure they don’t lose their reflection qualities if in case they get wet. Very large binocular telescopes were also designed for military use at sea.

At the present time amateur astronomers also commonly use binoculars. With the help of these binoculars it becomes possible to see Pallas, Neptune, Ceres etc that are invisible to naked eye. Amateur telescope makers have designed very large binoculars using two refracting or reflecting astronomical telescopes. Binoculars can be divided in to three categories Galilean binocular, Roof prism binoculars and porro prism binocular. The early binocular used Galilean optics that’s why they are known as Galilean binocular, they were designed after the invention of telescope in the 17th century. In Galilean binocular they used a convex object and a concave eyepiece lens. Then came the Porro prism binoculars they were named after optician Ignazio Porro. These binoculars have the advantage of folding the optical path so that the physical length of the binocular is less than the focal length of the objective. Achille Victor Emile Daubresse designed roof prism binoculars in the early 1870s. Most of the roof prism binoculars use either the Schmidt Pechan prism or Abee Koenig prism that are designed in such a way that they can erect the mage and fold the optical path.

For more information on different types and designs of binocular you can log on to the internet or you can also visit the local market both are excellent sources of information. You can also purchase binocular from a number of online shopping websites, buying a binocular from online shopping sites via internet is way to easy as compared to the market, because of the fact that binoculars are divided into different categories such as according to size and purpose, on these websites. At the present time there are a number of popular brands that are designing and producing binoculars that are used for a number of different purposes. Some of the popular brands of today are Canon, Nikon, Vortex, Leica, Tasco, Pentax etc. For information about these brands and their products you can log on to their official website.