There are several types of binoculars, therefore, it is good to know the particular application. Is it going to be for theater, opera, or horse racing? Maybe observation of nature, birds, or animals. If you need to use them on water, then you will definitely need waterproof binoculars. All binoculars are made for a specific application. With proper binoculars, you can observe the sun or use in the dark part of the day. Binoculars mostly differ by their magnification and optics as well as internal and external coating. Larger aperture binoculars have larger view range and are intended for outdoor activities. Smaller ones, on the other hand, will be handy indoors. Binoculars have two main characteristics - the first number is the magnifying power and the other is lens diameter. Binoculars 10X50 will have a 10x magnification and 5 cm lens diameter.