An equatorial mount compensates for the Earth’s rotation with the movement of a single axis. These mounts are essential for astrophotography, and extremely convenient for visual observers who want to easily keep their target in their field of view. These mounts are a pain to use for terrestrial viewing, however. There are several types of equatorial mounts. The German equatorial (shown in this video) is the most common. While they take a little getting used to, they are extremely stable and adaptable.