Lacerta M-Gen User Manual page 43

held. The latest 48 drift values are shown for the latest 48 frames, for each axis.
One time step (one frame) is one pixel horizontally while vertically the drift values
are scaled to the tolerance limit set. The tolerance interval is shown right next to
the frame with two short lines, the size of it is ±4 pixels to the zero.
As the tolerance value is changed so changes the appropriate axis' drift diagram's
scaling instantly.
This diagram is called guiding curve too.
Note: the screenshot example does not show a real guiding curve on a star but on
the background noise pattern only.
At the top left of the screen there is a progress indicator character, which is "rotating
right" as the new frames come from the Camera. If this is still, the Camera does not work (at
least properly).
To avoid close stars (in the same guiding window) disturbing guiding, use the 'partial'
image processing method or the NEW image processing mode. More on this at 5.1.10.4.
The guiding window "follows" the actual star in it (as written earlier). If the star closes
some edge of the window, the window is relocated to center the star in it. This star-centering
happens some time ie. during the calibration procedure. Don't bother with it, it has no effect
on the guiding.
This star-following behaviour is only active if the star could move off the current window
(ie. calibration). In other cases it remains in the same position (ie. guiding active).
Main imaging page (1/5)
5.1.10.1
This page contains the parameters of imaging and the autoguiding
can be started and stopped from here.
The screen items are the following:

gain
: (decimal, 1...9) profile
The same variable as the "image gain" at the Star Search screen. (They are identical.)
More on this value at 1.3.2. Changing the value takes effect imediately at the next
frame.

exp.
: (decimal, 50...4000 ms) profile
The same variable as the "expo.time" at Star Search screen. (They are identical.) The
used exposure (integration) time for taking images for autoguiding.

thresh.
: (decimal, 1...99 %)
The threshold value to discriminate star and non-star pixels for display. In the OLD
image processing mode, only the pixels above this are used for autoguiding.
Generally a value of 10% is useful and is above the noise at any gain (if the star fills
the dynamic range (check with "profile" display mode)).
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