Binocular An Overview

History and Mechanism

Binocular, a small instrument which is used today for countless purposes was invented by Sir Galileo Galilei (an Italian scientist) in 1609.  It was not really a binocular, but another form of it, a telescope.The underlying mechanism is same in both, simply put, there is some technical inter-play between different mediums (glass, water etc.) and the light that falls/passes through it and bends.

Basic Science of Binocular

This bending of the light is known as refraction, on the basis of which the whole working of binocular is found.  In 19th century, this idea was further developed into a microscope to observe organisms not visible to a naked eye.

Fascinating Features

The colorful coatings on a binocular in addition to increasing its attractiveness is actually applied to prevent the loss of light when it changes medium.  Military binoculars are the best for hunting and other such activities due to their special aspect of brightening an image in low light conditions that really helps during shady weather.  Additionally, sniper binoculars were specifically made to measure the distance and height difference from the target object.  Some of the toughest binoculars are for marines which are resistant to even the harshest weather and water proof (even total submersion).

Types And Usage Of Binoculars

The binoculars were introduced to the world by Lippershey on December 9, 1608. Thus the world was introduced with an instrument which will be highly helpful in all means. Since 1608, the binoculars have seen a phenomenal advancement.

Today’s binoculars are made of aluminium coated with silicon and the lenses and prism are of glass coated with anti-reflective materials.

Types of binoculars

Nowadays binoculars are available mainly in two types:

Roof prism and Porro prism. Roof prism is a low image quality, compact and durable while porro prism is highly quality, wider coverage and cheaper.

How they work

It consists of two objective lenses situated at each end, with focus on the object and bring light at the focus of the lens and reflect it back to the focus on the eyepiece lens, thus projecting a magnified image of the object.

Understanding magnification

Normally, binoculars are denoted with 8X and 10X magnification. This denotes that you will be able to see a object 8 times or 10 times larger. If you want the magnification number, then it will be magnification*lens diameter. Suppose, 10*42. Where 42 will be lense diameter in mm.


Binoculars have a range of usages like bird watching, astronomical, hunting, observation, trekking and military.

Binocular- Technical Features

When one is out on a jungle safari or sitting in the open gazing at the stars or during anight hunt, one of the important things that one must carry is binocular.

If you are going to order one, then there are certain important technical features to be considered before buying them. Binoculars come with aspecification like ‘axb’ where a and b are mere numbers based on which the following features have to be noted.

Magnification:The letter ‘a’ denotes the magnification and it represents how much times larger the object will be. In other words, the object will appear ‘a’ times larger than the original size.

Aperture: The letter ‘b’ denotes the aperture value. More clear and accurate will be the object in thedark when you choose one with ahigher number.

Field Of view: It represents how closely the object can be viewed through the lens. This also depends on the value ’a’ in the specification. As the value of magnification (‘a’) increases, thecloser will be the object which means you cannot cover larger area through the lens. So, if you like to cover more area then make sure the value of ‘a’ is less.

Exit pupil: Divide the number ‘b’ by ‘a’ and the result you get is the value of exit pupil. This number must be smaller than that of your eye pupil.

Take care of the above features and buy a perfect one.