Clock drives are devices used in looking at a particular star or celestial object such as the moon continuously from east to west. Because our platform, the Earth is rotating on its axis throughout the day, by using clock drives, one can follow the direction of the star or moon and keep track of it. Clock drives causes the telescope to rotate on its own axis, thus imitating the rotation of Earth in its axis.

Clock drives rotate once every two minutes because the apparent diameter of the specific focal changes within this period. One must remember that the higher the magnification that he is using, the smaller the celestial objects appear in the formed images. Using clock drives allow astronomers and photographers to utilize longer focal lengths and thus provide them longer exposure of a particular view field without the worry of the blurring of images caused by the Earth’s rotation.

Almost all of the telescopes made today are already equipped with a clock drive, and it imitates the exact diurnal variation of the Earth. Some clock drives are battery operated which let the user be worry-free from finding the nearest AC access while some of them require the use of electric current.