4
5
2) Guide Scope
You will need an additional telescope for guiding, referred to as a guide scope.
The guide scope is mounted on top of, or beside the main imaging scope.
Adjustable guide scope tube rings (available from Orion) are recommended
and allow you to move the guide scope around without moving the main
imaging scope (Figure 2). The guide scope is adjusted in the same fashion as
a finder scope.
Alternatively, the Orion X-Y Guidestar Finder can be used instead of adjustable
guide scope rings. The X-Y Guidestar Finder moves the autoguider laterally in
the focuser and imaging plane to find a guide star.
Because of the high resolution and accuracy of the Solitaire, you do not need a
large guide scope; any small refractor will serve well for this purpose. Separate
refractor optical tube assemblies, such as the Orion Short Tube 80, make
excellent guide scopes.
Note: Most refractor guide scopes will need an extension tube to reach focus
with the StarShoot Solitaire. A diagonal is an acceptable alternative to an
extension tube, but not preferred.
An alternative to using a separate
guide scope is an off-axis guider. An
off-axis guider uses a prism to inter-
cept a small portion of the light path
in front of the camera, thus allow-
ing the camera and guider to use
the same telescope. Off-axis guid-
ers require a large amount of inward
focus travel which is why they are
most commonly used in catadiop-
tric telescopes, such as Schmidt-
Cassegrains or Maksutov-Cassegrains.
3) Mount
An equatorial mount with dual axis motors and a RJ-12 autoguide port is
required. Just about any equatorial mount equipped with an autoguide port
will work with the Solitaire (Figure 3a). The Solitaire is “ST-4” compatible which
uses the same pin out configuration as the first generation CCD autoguiders
(Figure 3b). Most computerized GoTo mounts also have this autoguide port.
For short exposure deep space photography (typically 45 seconds or less)
the Solitaire can successfully guide with a computerized altitude-azimuth or
fork mounted telescope, popular among computerized Schmidt-Cassegrain
telescopes. However, guided exposures longer than one minute in an altitude-
azimuth mount will cause field rotation to occur in the image. An equatorial
mount will yield the best overall performance for guided deep space astro-
photography.
Figure 2.
Adjustable guide scope tube rings allow you to adjust the position of the
guide scope without moving the main imaging scope.
Adjustable guide
scope tube rings
Main
imaging scope
Guide scope
(Orion ShortTube 80)
Figure 3a.
The Solitaire works with any mount equipped with an ST-4 compatible
autoguide port, shown here on the Sirius EQ-G mount.
Figure 3b.
This is the autoguide port
pin diagram for the ST-4 compatible
mounts.