Buying Binoculars: How to choose the right binoculars?
When buying their first binoculars, most people don’t know where to start. With today’s technology offering the world’s best and most powerful binoculars, most novice buyers’ first reaction is: What do these numbers mean? or How do I choose the right binoculars for me?
In our Buying Binoculars Tips series, we will review the most important features you need to consider when buying your new set of binoculars.
Binoculars Magnification / Power - The power or magnification of a binocular is the first thing you need to examine when choosing binoculars. Magnification is usually the first number, in a series of two numbers, which tells us how much closer the object will appear in the binoculars, as opposed to the naked eye. For example, the Barska 25×40x100 jumbo binoculars provide us with a 25 power of magnification, which means you will see the object twenty-five times closer then with your naked eye.
Binoculars Objective Lens - When you stumble upon the objective lens in a binoculars technical data sheet, it means the front lenses of a binocular, which are represented in millimeters and serve to collect light. The larger the objective lens, the more light a binocular will gather, providing you with a brighter image.
Keep in mind that the size of the objective lens will directly impact the physical size of the binocular. For example, while both the Nikon 10×32 Premier LXL Binoculars and the Nikon 10×70 Astroluxe Binoculars have the same power or magnification, the 70mm objective lens will provide a brighter image, but the 10×32 will be smaller and lightweight.
Binoculars Field of View or Wide Angle - The size of the viewing “window” through a pair of binoculars is called the field of view. In most cases, the field of view of a binocular is measured in feet in relevance to a distance of 1000 yards. The field of view size will change according to the binoculars magnification power; for example, a higher magnification binocular will have a smaller field of view, since your main objective is to focus on a smaller, more detailed area.
Keep in mind that the power is not the only factor influencing the field of view. The body style of the binoculars is also important. For example, porro prism binoculars, like the Leupold 8×42 Cascade Binoculars with their familiar zigzag profile (as seen on the left) will have a larger field of view than the ones with their roof prism straight-line design (as seen on the right).
 Leupold 8×42 Cascade Binoculars |
 Leupold 8×42 Cascade Binoculars |
Exit Pupil - The size of the shaft of light from the binoculars eyepiece to the user’s eye is the exit pupil; you can actually see a bright circle of light in the center of your binoculars eyepiece.
Expressed in millimeters, the exit pupil is usually calculated by dividing the power by the objective lens. For example a 7×35 binocular has an exit pupil of 5mm. The larger the exit pupil, the brighter the image will look. Therefore, when considering binoculars for low light use, you should examine the exit pupil number.
Close Focus Binoculars - The minimum distance from the subject necessary for the binocular to focus clearly, is called the close focus. Binoculars are used for long distance viewing as well as for short ranges. That is why the close focus, usually expressed in feet, is another important factor in choosing a binocular.
Eye Relief - The eye relief is the distance calculated from your eye to the binoculars eyepiece. For people who wear glasses in order to sharpen their eyesight this feature is crucial, since buying binoculars with an extended eye relief will make binocular observing with eyeglasses - easier.
