Click for detail
How To Use Binoculars
How Binoculars Works
Type Of Binoculars
How To Choose Binoculars

Page 1 | Page 2


Binoculars are essentially two low-powered telescopes joined together, so that you can look through them with both eye instead of just one. For certain aspects of skywatching they are the best instrument of all to use.

For the amount of money you would pay for a poor quality small telescope, you can purchase a well-made pair of binoculars with quality optics that will last a lifetime. Through binoculars you will be able to see the craters on the Moon, the moons of Jupiter, and five or ten times as many stars as can be seen with the naked eye.

One of the best ways to use binoculars is to be seated on a reclining garden chair, preferably an adjustable one, so that you can see it high for views near the horizon, and low for observations higher in the sky. If the chair has arm-rests, you can rest your elbows on them to hold the binoculars steady, enabling you to see the stars as steady points of light rather than as a bunch of flitting fireflies. Another way of balancing your binoculars is to simply lean against a wall or fence.

Observers often mount their binoculars on a camera tripod, and you will certainly find a tripod necessary if you are using a larger pair, as they can be quite heavy and a strain to hold for any length of time.



Binoculars are like two telescopes mounted side by side. So, how do telescopes work?

At the front of each telescope is a lens - either an objective or a field lens. This gathers light from whatever it is you are looking at. Let's says you're looking at a bird. The objective or field lens magnifies the image of the bird, but this image is upside-down. Not very useful at this point.

If you are using prism binoculars (and most likely you are - they are the most popular kind), a prism in each tube reverses and inverts the image of the bird. In field glasses, there's a second lens instead of a prism.

The light then travels down the tube, and through a lens in the eyepieces. The bird is magnified even further. Good binoculars will give you an accurate and detailed look at the bird.eople

A prism is a solid piece of glass that functions as a mirror, but without a mirror's reflective backing. Light rays that have entered a prism cannot get out if they strike a surface at too great an angle. Instead, they reflect back, as if from a perfect mirror.

As a conclusion, all binoculars still have these three parts. An objective lens focuses an upside-down image. A set of prisms turns the image right side up. And an eyepiece magnifies it. Though modern eyepieces and objective lenses are each comprised of multiple elements, their basic functions remain unchanged.



Prisms are used in binoculars so that the image you see is around the right way. Otherwise it would be upside down and switched left to right, as it is in a simple telescope.

The two main styles of binoculars differ mainly in the orientation of the prisms that are used. The porro prism is simpler than the roof prism, and is the one of the most commonly used in binoculars today. The roof prism is more expensive, but is quite a bit lighter and is more compact.


Sky Observing
History Of Sky Observing
Observing Techniques
Celestial Showcase
Eyepieces & Filters
Contribution Of The Amateur Astronomers
Copyright © 2005 skyteoh.com. All rights reserved.