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   As with many other objects shown in Guide,  you can use "show at"
to tell Guide only to show the images at certain fields of view.  By
default,  images are shown only between zero and 1.6 degree fields of
view.  (They don't tend to look like much of anything above 1.6 degrees,
and there can be so many images at larger fields of view that the program
drags to a stop while drawing them.)

   By default,  Guide will show images in "normal" mode,  with stars
bright and the background dark.  Click on "Invert images",  and they
will be shown in a photographic negative mode,  with the background
bright and the stars dark.

   If you've extracted large numbers of images from CD-ROMs,  you may
want to free up the hard drive space they consume.  Clicking on "Clear
RealSky Images" will do this.  You'll get an "are you sure" message,
and if you confirm,  the images will be deleted.

   To extract RealSky/DSS images from CD-ROM,  you should first center
on the area of interest,  then click on "RealSky/DSS from CD".  You'll
get a dialog box in which you can tell Guide a bit about what size image
you want and whether you want to extract it from DSS or RealSky North or
RealSky South CD-ROMs.  There may be more than one scanned image
covering the region you're interested in;  if so,  you can select the
one you want to use..  (Though in general,  you'll just want to accept
the default image.)  You'll be asked to insert a given CD-ROM, and the
image will be extracted from it.  After this,  you'll be asked to put
the Guide DVD back in the drive,  and Guide will draw a chart with your
newly-extracted image shown.

   "Add DSS Image" can be used to import a DSS image you've downloaded
manually from the Internet.  You'll normally want to use the "DSS from
Internet" option described below,  but there are still some holdouts
who prefer to get DSS images from various servers,  then import them
to Guide using this function.  The servers are listed on the Project
Pluto Web site.

   You can visit any these sites and get a DSS image in FITS format.
(GIF and other formats won't work.)  Click on the "Add DSS Image"
option, and specify the name of the image you have just downloaded.
It will be shown just as if you extracted the data from the CD;  only
the method of importing the image is different.
                               
   To get DSS images from the Internet,  you should first center
the chart on the area of interest,  and zoom in or out to cover
the desired area.  You can then select if a DSS-1,  or DSS-2 R,
or POSS (Palomar Observatory Sky Survey) red or blue plate,  or
any of several others, should be used.

   DSS images from the Internet are limited to a maximum dimension
of 15 arcminutes;  ask for a larger dimension,  and it will get
chopped down to that size.

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