65series 25/40 x100 telescope, once thought to be in the domestic large binocular telescope of Kings, so-called "big MAC" land, excellent optical performance.Purpose of type 25/40 x100 telescope, once thought to be in the domestic large binocular telescope of Kings, so-called "big MAC" land, excellent optical performance.One, the purpose of the development of the telescope before the sino-soviet tension, with big ratio of PLA products made of telescope mainly Germany and the Czech republic, after the sino-soviet tension, source of supply is broken, forces a mass of just one, a serious shortage, coastal defense, frontier defense and field artillery need for long-range reconnaissance big powerful telescope.1962 SanJiBu instructions of the development of large ratio telescope, due to lack of experience and information, yunnan north optical (298 factory) requirements allocated two prototype reference.In March 1963, 3 in1 forces design products structured reference west German Zeiss 20 ~ 40 times the continuous variable times samples of surveying and mapping design