To understand the binoculars, we start with the identification of the surface of the telescope. For example, the a telescopes on the surface of the Zoo shoulder printed with the words "10 X 50", "10" said the telescope magnification is 10 times times, that is, through the telescope, viewing 100 of the object is equivalent to the distance object 10 meters to watch him. The following "50" is the mirror's objective Lens (formerly composed of an optical glass lens) with a diameter of 50mm. The larger the diameter, the stronger the concentrating capacity, that is, the more dark objects can be seen, the higher the image quality. However, I often in the streets or downtown can see some personal small vendors carrying a lot of binoculars, the telescope logo directly labeled XXX, that is, magnified hundreds of times times, the caliber of hundreds of mm binoculars? Does he have to carry such a double cylinder? Therefore, the kind of garbled logo of the telescope is generally a toy, the use of ordinary window glass (also known as clear glass), the prism is also clear glass, so that the telescope has no optical quality said.