Binoculars (or binocular telescopes) are basically side-by-side telescopes that allow a person to look at faraway objects while using both eyes. Because both eyes are involved when looking through a set of binoculars, not only do you get the benefit of magnification (like a telescope), but the combination of very slightly different viewpoint of each eye -- just like your unmagnified vision -- also produces a 3-D image. Because of this, binoculars can be the best friend of any serious observer or hobbyist. You can find binoculars in such a wide range of places as the theater; in the hands of your local birdwatcher; mounted on a pedestal in front of popular tourist sites; most astronomers count them as an essential part of their gear; and the military counts on them as well.
Binoculars are about as easy as they come to use. Most fit easily into a pocket, pocketbook, or bag, and as far as price goes, you can purchase a good pair without breaking the bank. In this article, you will learn how to assess your match your new binoculars to your observing goals, compare the most common types of binoculars will find in the store, and then choose the best pair of binoculars for you.
When choosing a pair of binoculars, the first and most important step is to know what you're looking at. If you want to use your binoculars to look into the heavens and observe distant stars, you're going to need a much more powerful set than the average birdwatcher. You may even want to consider mounting your heavy-duty binoculars on a tripod. The more you want to see, the farther away it is, and the greater the detail of the image, all determine the size and weight of the binoculars you choose.
Your first step is to look at the binoculars' power measurement. The power level of binoculars is categorized by paired numbers, for example 6 x 10. The number that comes first tells you the amount the image will be magnified. So in this case, the image will be magnified to six times what you could normally see. The second number gives you the diameter of the lens in millimeters. The second number tells you how much light will enter your binoculars. The larger the lens, the more light. But the larger your lens and the greater magnification, the heavier and more bulky your binoculars become. As a result, choosing the right binoculars becomes a juggling act of weight, size, detail, and magnification.
Binoculars come in two major flavors: Roof Prism Binoculars and Porro Prism Binoculars. You're much more likely to come across Porro Prism Binoculars in your travels than Roof Prism Binoculars. Porro Prism Binoculars are made up of two lenses with prisms in the front. These prisms bend light towards the back where the eye-pieces reside. In contrast, your more expensive Roof Prism Binoculars basically look like a pair of telescopes placed side-by-side in front of your eyes. That's really what they are, with the addition of an image correcting prism on each side.
It's worth taking a few moments to go into a bit more detail about the importance of aperture (lens diameter) and magnification. Just like with the telescope, the diameter of your lens is critically important to how far away and how detailed your images will be. If you're looking at the stars, an astronomical binoculars' average size is about 50 mm. Much below that, and you're better off keeping your observations on the Earth. In conjunction with lens size, the second aspect to consider is magnification. Most binoculars fit somewhere in 6x and 20x magnification spectrum. Much higher than that, and you'll be better off mounting your binoculars on a fixed tripod if you expect to use them. Just like with a microscope, or telescope, the higher the level of magnification, the more narrow the view.
But there is one caveat. If you're using your binoculars to observe the night sky, where you live plays a large role in what level of magnification will work best. In general, the lighter the sky, the higher the level of magnification your eyes will need. If you live in a city or suburb, you'll need to buy binoculars in the range of 8x and 12x -- a good choice would be 10x. But if you are observing under skies that are darker and not obscured by streetlights, then go for somewhere between 6x and 9x -- we recommend 7x. Whatever magnification you choose, stay clear of zoom binoculars, as they have problems when it comes to precision in coordinating magnification between both eyes.
Taking into account your goals, magnification, and lens size, you're ready to go out and really see what's out there. Now you have the tools you need to go out there and take the best pair of binoculars for you.
