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full color saturation.  Turn it to,  say,  50%,  and the stars will
appear to be somewhat more realistically colored.

   The "blurring" option is another gesture toward realism.  Set it
to a non-zero value,  and Guide will draw stars with softer edges,
making them look a little more circular.  A value of 1 to 3 is usually
considered visually pleasing.  As with many of the settings in this
dialog,  though,  your personal preferences may be very different.

7b:  The Data Shown menu                      

   The Data Shown menu lets you control what celestial objects are
shown on the chart,  and the manner in which they are shown.
                                                     
   In the dialog box,  you are given a list of fifteen classes of
objects controlled by the Data Shown menu/dialog:

Messier
NGC + IC
Galaxies
Nebulae
Planets
Variables
NSV
Open clusters
Asteroids      
Gal Clusters
Comets
Globulars
Planetaries
Dark Nebulae
Satellites

   Each object class is followed by buttons to turn that class "on",
"off",  "auto",  or "fixed".  When a particular class of objects is
turned On,  all objects of that class will be shown, regardless of
magnitude.  When Off, none will be shown.  When set to Auto or Fixed,
all objects brighter than the magnitude limit for that class will be
shown.

   The difference between 'fixed' and 'auto' is a simple one.  In
'auto' mode,  Guide will automatically adjust the limiting magnitude
as one zooms in or out,  in an attempt to maintain a constant density
of objects. (This is always done for stars,  for example.)  But in
'fixed' mode,  you are essentially telling Guide that you want a class
of object to be shown to a particular limiting magnitude,  and that
the zoom level should be ignored.

   If an object class is turned On or Off,  the magnitude limit is
irrelevant,  and is therefore grayed out.


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