Fork

The fork mount is really a modification of the equatorial mount. It is used primarily with Schmidt-Cassegrain telescopes. The fork is designed as a heavy-duty mount that can support a large amount of weight. Telescopes that use these mounts are generally very heavy, due to their large aperture lenses and mirrors. The fork mount allows the telescope to swing between the arms of the fork to adjust the Declination (Dec.) setting. The fork itself rotates on its axis to adjust the Right Ascension (R.A.) settings. Setting circles allow objects to be "dialed-up" according to their coordinates after the mount has been properly aligned with the Earth's axis. Fork mounts usually always contain motors, which allow automatic tracking of objects by correcting for the Earth's rotation. Some of the more advanced fork mounted systems today also contain a computer interface, which allows the telescope to find an object by simply entering its coordinates into a keypad.