Starlight Xpress CoStar - Manual (Page 4)

CoStar handbook Issue 1 May 2011
Guiding with the Starlight Xpress software
With the CoStar connected to the PC and mount, open ‘CoStar.exe’ and find the ‘Set program defaults’
menu under the ‘File’ heading. If this is the first run of the software, you will get a warning about the
‘ini file not found’, but ignore this and click on OK – you can then open the ‘Set program defaults’
menu. You should see a screen similar to the one shown below:
The settings shown above are generally satisfactory as a starting point, although some will probably
need refinement for best results. In the example shown, the ‘autoguider socket’ on the CoStar is
providing the control signals to the mount, but you might alternatively use the ‘LX200’ mode via the
serial port of the computer, if this is preferred. The Guiding Parameters are set to 6 pixels per second,
which corresponds to the typical drift rate of a 1000mm focal length guide telescope when the mount is
guiding at 0.5x sidereal speed. Longer focal lengths and/or higher guiding rates will require a larger
value to be set so as to avoid excessively fast corrections, which can cause erratic guiding or even
oscillation of the guiding errors to either side of the guide star.
Once the defaults have been set to values which you think will be approximately correct, save the
settings and open the ‘View’ menu. In this you will see an option called ‘Max palette stretch’. Open
this and check the ‘Activate stretch display’ check box. This will automatically boost the image
brightness so that faint guide stars can be easily seen – if necessary, you can adjust the slider for the
best results.
Now click on the camera icon to open the CoStar control dialog, as below: