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Follow these steps to adjust the focus of the guide scope:
1). Insert an optical eyepiece into the eyepiece holder of the guide scope. Activate tracking of the
mount. Center a bright star in the eyepiece’s field of view.
2). Remove the optical eyepiece and replace it with the SynGuider.
3). Use the “+” or “-” buttons on the hand pad to set the exposure time to 100 milliseconds.
4). Use the NOISE Menu to set the noise control level until the LCD is free of background noise.
5). Adjust the focuser of the guide scope until the image of the bright star appears in the LCD as a
blank dot. Continue to adjust the focuser until the the blank dot appears to be smallest, suggesting
that the image is in focus. At this point, if you continue to turn the focuser you will see that the dot
becomes larger again. The BRI reading will increase as the image comes into focus. If the BRI
reading increases to over 100, use the “-” button to reduce the exposure time to avoid
over-exposure. If the BRI reading still keeps high with minimum exposure, try to use a fainter star
for focusing.
6). Use the "ZM STAR" menu to change the zoom level to show more details of the star image.
Fine tune the focuser to obtain the smallest star image and the highest BRI reading. Lock the
focuser of the guide scope and remove the SynGuider from the guide scope.
7). Now it is the time to make a par-focal eyepiece for later use. A par-focal eyepiece can be used
to locate the guide star, or to adjust the focus of the guider scope for subsequently setting up the
guider scope.
Follow these steps to make a par-focal eyepiece:
OPERATING UNDER THE NIGHT SKY
