What's the best amateur telescope for astrophotography?

With few exceptions (notably the sun, the moon, the brightest stars, the brightest planets and rare transient phenomena such as bright comets and meteors), celestial objects are typically very faint. In order to obtain good photographic images, one must therefore use long exposure times and highly sensitive film or CCDs. Because of the Earth's rotation, all celestial objects show an apparent motion over the sky, and long exposure times inevitably require some sort of compensation to avoid blurred images. Telescopes equipped with motorized equatorial mounts can compensate the Earth's rotation but need a precise control of motor speed. To achieve the best possible compensation, a separate telescope ("guidescope") attached to the same mount as the camera, or an off-axis guider integrated into the telescope used for photography is used. Both these devices make use of a reference star that is observed in a crosshair eyepiece and whose deviation from the ideal position is continually used to correct the motor speed. Advanced systems employ "autoguiding", which automates this process by using a separate CCD with which a tracking star is monitored and which controls, through a specialized electronic system, the mount's motors.