Lacerta M-GEN User Manual page 51

sharp and short focal length optics because this easily maps the star into one or only
some pixels that is not enough for detecting the position in fractions of a pixel. In this
case slight defocusing of the guiding star will help.
7.3 Example for setting up and starting an autoguiding
 Navigate to the "guider setup" screen! (From main menu:
.)
setup
 Enter the real values into the screen's items. The focal length is enough to be given
roughly. For the actual autoguiding speed used, see Your mount's (hand)controller.
 Navigate to the LiveView screen (5.1.8)! (From main menu:
With changing the imaging parameters, find a star in the field of view (the brightest
possible but above magnitude of 4 might be way too bright...). Check with slightly
pushing the tube that the seen spot is a real star and is not a hot pixel structure (the star
must move by the puhsing). Choose one of the stars and You get to the Guiding screen
(5.1.9).
As an alternative You can use the automatic star search function also (5.1.7) that may
take more time but is more comfortable and immune to single hot pixels.
 On the 1 st
page of the Guiding screen (5.1.9.1) You can optimize the imaging
parameters (gain and exposure time). This can be done the following way:
o Set the display mode to "profile";
o Change the parameters so that the star covers the full dynamic range (the
profile of the star reaches the bottom of the window), it's not a problem if the
bottom is only near to it or sometimes it saturates in some columns. Take care
of the followings:
 the exposure time should be as much as possible, as many as Your
 the gain should be as low as possible for the lowest readout noise.
(An automatic procedure will be included soon to do this without human interaction.)
 Change to page 2 (5.1.9.2)! Delete the previous calibration (if any) and start a new
one. Re-run the calibration until an acceptable orthogonality is measured (over 90% is
near perfect).
 Change to page 3 and 4 (5.1.9.3) and set up the guiding parameters for the axes as
advised.
 Change to page 1 (5.1.9.1) and start the autouiding!
Soon the first correction signals will be indicated by the red LEDs as short or longer
flashes. By monitoring these signals You can trace what the guider is doing. If Your
mount has some typical errors (as mine has) those can be observed easily by watching
mount's periodic error's rate allows and as much as it smoothes the
seeing enough not to chase that;
Guiding / Guider
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Guiding / Live View
.)