This procedure need never be repeated. To focus the telescope onto the film plane, the eyepiece and holder are attached to the tracker using thumb screws. Magnets help guide the holder into position. The telescope is then focused as usual while viewing through the eyepiece. The eyepiece holder is removed from the tracker and replaced with the camera.
Exposures are now in perfect focus.
The focuser and camera are easily interchanged. An extension tube can be placed between the tracker and camera for eyepiece projection. The extension uses the same method of attachment as the camera and focuser. The result is perfectly focused planetary images. Since the camera lacks a mechanical shutter, the hat trick method must be used.