Binoculars are used to see distant objects clearly by magnifying an image which is viewed through the binoculars. We are talking about objects that are too far away to be seen with the naked eye.
Binoculars look like a simple piece of equipment, but the principle with which they work is fascinating. Binoculars are used by people who enjoy outdoor activities such as bird watching, hiking, sailing, and they are essential tools used by military personnel.
The principles with which binoculars enlarge images to make them more visible to the user are based on physics. This video presents a good representation as to how binoculars work.
What are the Essential Parts of Binoculars?
Binoculars feature high-quality lenses that have been positioned in a way that objects viewed are magnified.
In binoculars, the main parts are the objective lenses, prisms, focus wheel, the barrel, and eyepiece. To properly understand how binoculars work, let us find out the functions of each of these essential parts. This is explained in a little more detail at this link.
The Objective Lenses in Binoculars
These are a set of convex lenses that have been skillfully positioned to make it easy for the user to view distant objects. The lenses are magnifiers.
The prisms in binoculars make it possible to view distant objects in an upright frame, without the prisms, you will view inverted images.
The eyepieces in binoculars are designed to accommodate the users’ eyes and help with focus when viewing distant objects.
The central focus wheel is used to readjust the images’ sharpness when viewing objects at different distances.
The barrel makes it easy to grip the binoculars firmly while it is in use.
How Do Binoculars Work?
According to physics, two convex lenses placed together can magnify an object viewed through the lenses, according to https://www.explainthatstuff.com/binoculars.html.
The binoculars work with two convex lenses. The first lens is called the objective lens. The light rays from the distant image pass through the objective lens. But this image is inverted.
The inverted images from light rays that pass through the first convex lens are rotated to become an upright image when it hits the prisms.
Two prisms are carefully positioned in the binocular’s barrel – between the two lenses that act as magnifiers.
The prisms in binoculars flip the inverted images at 900 and they are placed at ninety degrees in the barrel. The first prism flips the inverted image at 900 to the second prism, which does the same thing.
The final image that hits the second lens is upright because it has been flipped at 1800 by the prisms. This is the image seen by the user.
The focusing wheel is an adjusting feature positioned between the two cylinders of the binoculars. It is used to re-focus the displayed image, which always gets slightly “out of focus” when looking at objects at other distances. The focusing wheel increases or decreases the air gap separating the lenses in the binoculars.