What type of binoculars is best for astronomy?
As you may have already deduced, the porro prism design is best for astronomy—but remember that any pair of binoculars is better than no pair of binoculars! Try this simple experiment: Cover one eye while looking at the starry sky. How many stars can you see in a given field? Now look at it with both eyes. Chances are you’ll see close to half as many more. The act of viewing the sky with two sets of eyes not only increases contrast, but allows a “stereo” view. When choosing a porro prism model, you are using a design that allows the maximum amount of light to enter your eye. The larger the aperture—the light gathering surface—the more light is collected, making images brighter. But, remember—this also means added weight. The secondary lens is more directly related to your eyes’ ability to see the light. Let’s discuss this equation… For a pair of 7 X 35 binoculars, the “7” represents the amount of magnification, while the “35” represents the diameter of the front lens. If the aperture
