Lodestar X2 handbook Issue 2, August 2014
A typical set up might consist of an inexpensive 80mm F5 refractor ‘piggybacked’ onto an SCT, with
the Lodestar X2 fitted directly into its focus barrel. Many such telescopes are designed to be used with
an inverting prism ahead of the eyepiece and so the focuser may be too short when the Lodestar X2 is
inserted directly. In this case, an extension tube may often be made from a cheap Barlow lens assembly
with the lens removed. This configuration can be seen in the picture below.
The Lodestar X2 attached to an 80mm F5 guide ‘scope
The focal length of your guide telescope is not especially critical for good guiding, as the guiding
software searches for the ‘centroid’ of the guide star image and can resolve shifts of far less than 1
pixel. Using a guide scope with a relatively short focal length (between 300 and 500mm) makes guide
star finding very easy and this is a recommended setup for general purpose guiding.
The control of your telescope mount will depend on what inputs are provided. The Lodestar X2 output
connector supplies 4 pull-down lines and a common return line to simulate an ‘ST4’ style autoguider
output. The lines are isolated from the Lodestar X2 electronics by opto-isolator chips and so there is no
risk of damage when connecting the outputs to mounts with unprotected electronics. A standard ‘RJ12’
