Binoculars are an excellent tool to help bring the action up close and personal, whether observing birds in a nature preserve, football players in a stadium, or your favorite rock star at a concert. Yet different uses require different types of binoculars. With hundreds of different models to choose from, it can be difficult to figure out the best pair to buy. Yet with the understanding of a few basic concepts, choosing a pair of binoculars can be made much easier. Let's take a look at some of the most important concepts when choosing a pair of binoculars.
Magnification – Magnification is the first number in a pair of binoculars. So when you see a pair of binoculars labeled as a 10x50, the magnification is 10x, or 10 times. That means that the binoculars will make the object appear 10 times closer.
So is more magnification always better? Not necessarily. When you increase the magnification, the object will appear closer, but the image will shake more due to the magnification and the field of view will get smaller. Most binoculars are between 7x and 10x. As a general rule, if you are going to be closer to the subject, choose a lower magnification. If you are further away, choose a higher magnification. So if you have excellent tickets to your favorite football team, go for something in the 7x range. If you are a bit higher and further back, then choose a higher power around the 10x range.
Aperture – Aperture is simply the size in diameter of the front objective (in millimeters). The front objective is the lens (usually glass) in the front of the binoculars. If you look at our example of the 10x50 binoculars, the aperture is the number 50. So the 10x50 binoculars have a magnification of 10x and an aperture of 50mm. The bigger the aperture, the more light the binoculars will gather and the brighter the image will be. Also, a larger aperture will provide greater resolving capabilities providing greater detail. However, a larger aperture will also make the binoculars larger, heavier and more expensive.
So what is the best size to choose? Think about where and when you will be using the binoculars. If you are using the binoculars in a low light situation, such as at nighttime or in a darkened theatre, then go for a larger aperture in the 35mm to 50mm range. If you will be in daylight, then you can do fine with something in the 20mm to 35mm range.
Also make sure to think about portability. If the binoculars have to go into a purse, pocket or other small area, then go with a smaller aperture in the 20mm to 30mm range. If portability is less of a factor, then a full size pair in the 35mm to 50mm range will provide a brighter, higher resolution image.
There are a number of additional concepts and specifications for binoculars, but magnification and aperture are the two most important. Understanding these two factors can make choosing a pair of binoculars much easier. So whether you are looking for binoculars for hunting, sports, birding, boating or any other use, you are now that much closer to finding the right pair of binoculars.