Equatorial mount

The advantage of an equatorial mount lies in its ability to allow the instrument attached to it to stay fixed on any celestial object with diurnal motion by driving one axis at a constant speed.

[3] They may also be equipped with setting circles to allow for the location of objects by their celestial coordinates.

Digital setting circles take a small computer with an object database that is attached to encoders.

A special instrument tracks a star and makes adjustment in the telescope's position while photographing the sky.

In new observatory designs, equatorial mounts have been out of favor for decades in large-scale professional applications.

The mount was developed by Joseph von Fraunhofer for the Great Dorpat Refractor[5] that was finished in 1824.

Most modern mass-produced catadioptric reflecting telescopes (200 mm or larger diameter) tend to be of this type.

The original English fork design is disadvantaged in that it does not allow the telescope to point too near the north or south celestial pole.

This gives equatorial tracking to anything sitting on the platform, from small cameras up to entire observatory buildings.

A large German equatorial mount on the Forststernwarte Jena 50cm Cassegrain reflector telescope.
Principle of operation and effect of an equatorial mount, assuming the subject is far enough that parallax is negligible
German equatorial mount
Open fork mount
English mount on the Hooker telescope
Horseshoe mount on the Hale Telescope
Cross-axis mount.