My new mount is a iOptron GEM45. This is a German Equatorial Mount that works by tracking the rotation of the earth using the RA axis. To do this it needs to be Polar aligned. The mount must face Polaris in the northern Hemisphere. To make this easier the mount comes with a camera mounted inside the HA drive, in the centre of the face of the mount. This camera can take a picture of the sky and plate solve where it is pointing. Then it can show you how much to move the mount on the HA and DEC axis to get Polaris exactly in the correct place. (Hr angle) for the mount to be polar aligned. This is call a iPolar camera. iOptron GEM45 and Altair Pillar The mount has a very precise RA and DEC worm gears with with 216 teeth with 128X micro-steps, with synchronous belts. (The drives use Synchronous belts to make sure that there is no backlash in the system.) This gives a resolution of 0.08 arcsec (200 PPS) and out the box it has periodic error accuracy of +- 7arcs with a 400 second cycle. Howev...