AZ800 800mm Ritchey-Chrétien AltAZ Telescope f/7 f/2.5 with Nasmyth focus The AZ800 is a high end RC telescope with nasmyth focus in a fork mount. It is driven by direct drive torque motors combined with high resolution optical absolute encoders for position feedback. The tertiary mirror can be rotated by a torque motor to any position, so that the telescope provides up to 4 usable foci. The focuser is also equipped with an absolute encoder. It shifts the secondary mirror.