Are you eager to watch a rare species of a bird? Do you want to capture Star light? Would you like to spot a boat on a remote horizon? Then you need to have a binocular.
Binoculars are a twin telescopes mounted on a single frame to facilitate two separate images entering each of the viewer’s eyes. Distant objects appear magnified with a single telescope. Binoculars have an additional advantage that the range of depth perception of the viewer is substantially increased. This happens so because the magnified images are seen with both eyes.
The hinged framework of binoculars allows distance adjustment between the telescopes. Some types are binoculars are provided with separate focusing of each telescope from the eyepiece. The term binocular now refers to the prism binocular, in which light after entering each telescope through its objective lens is first bent in one way and then the other by a pair of prisms before passing through one or more additional lenses in the eye piece. These prisms help in reducing the length of the instrument and enhance the viewer’s depth perception by increasing the distance between the objective lenses.
The specification of binoculars in often made by an expression like ‘7 X 35,’ ‘10 X 50.’ The numbers in these expressions are very important because they indicate the capacity of the binoculars. The first number indicates the number of times that the binocular magnifies an object and the second number indicates the diameter of either objective lens in millimeters.
The size of an objective lens matters in measuring the amount of light I can gather for effective viewing.
