Write about construction and use BINOCULAR.
Answers
Almost from the invention of the telescope in the 17th century the advantages of mounting two of them side by side for binocular vision seems to have been explored.[1] Most early binoculars used Galilean optics; that is, they used a convex objective and a concave eyepiece lens. The Galilean design has the advantage of presenting an erect image but has a narrow field of view and is not capable of very high magnification. This type of construction is still used in very cheap models and in opera glasses or theater glasses. The Galilean design is also used in low magnification binocular surgical and jewelers' loupes because they can be very short and produce an upright image without extra or unusual erecting optics, reducing expense and overall weight. They also have large exit pupils making centering less critical and the narrow field of view works well in those applications.[2] These are typically mounted on an eyeglass frame or custom-fit onto eyeglasses.
Binoculars with Keplerian optics
An improved image and higher magnification is achieved in binoculars employing Keplerian optics, where the image formed by the objective lens is viewed through a positive eyepiece lens (ocular). Since the Keplerian configuration produces an inverted image, different methods are used to turn the image right way up.
Binoculars with erecting lenses
Cross-section of relay lens assembly – system 2.
In aprismatic binoculars with Keplerian optics (which were sometimes called "twin telescopes") each tube has one or two additional lenses (relay lens) between the objective and the ocular. These lenses are used to erect the image. The binoculars with erecting lenses had a serious disadvantage: they are too long. Such binoculars were popular in the 1800s (for example, G.& S. Merz models), but became obsolete shortly after the Karl Zeiss company introduced improved prism binoculars in the 1890s.[3]
Binocular is an optical equipment which is used to watch objects which are situated far away and not watchable with our bare eyes.
Normal binocular's structure is very simple.Two funnel like metal bodies are connected with each other,which are at a distance similar to our two eye's between gap.
And the openings of the funnel's both end is almost similar sized where a concave lens and a convex lens are situated for the optical zooming procedure.