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a.
Figure 3. a) Installing the DMGS on an optional dovetail bar. b) Ready for mounting on
telescope tube rings or side-by-side saddle.
Autoguider
nosepiece
Thumbscrews
a.
Figure 4. a) An autoguider with a 1.25"
nosepiece can be inserted into the focuser
and secured with the two thumbscrews.
b) Threading an autoguider directly onto
the T-threads is the most secure mode of
attachment. c) The StarShoot AutoGuider
makes a perfect match for the DMGS.
plate onto a dovetail mounting plate (Figure 2b) by inserting one of the supplied
1/4"-20 socket head screws up through an unthreaded hole or slot in the dovetail
plate and into the ¼"-20 hole in the center of the adapter plate. Tighten with a
3/16" Allen wrench (user supplied). We have provided two different socket head
screws for your convenience, one is ½" long, the other 1" long. Choose the one
that best fits your mounting plate. Figure 3 shows the DMGS being mounted on
an optional Orion narrow dovetail plate.
attaching Your autoguiding camera
A guide camera can be coupled to the focuser either by a) inserting the
camera's 1.25" nosepiece into the focuser as far as it will go and securing it with
the two thumbscrews (Figure 4a), or b) if your camera is equipped with female
T-threads, by threading the camera directly onto the male T-thread flange of the
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b.
T-threads
b.
c.
focuser. Figure 4b shows the Orion
StarShoot AutoGuider being threaded
onto the T-threads of the helical
focuser, and then fully installed (Figure
4c). Using the T-threads is the most
secure mode of camera attachment.
Focusing with the Deluxe Mini
Guide Scope
The DMGS features a precision helical
focuser that makes it easy to focus
your guide stars quickly and precisely
(Figure 5). The focuser, made of
machined, anodized aluminum, is the
"non-rotating" variety, meaning the
guide camera does not rotate when
focus is adjusted, but rather moves
in or out in fixed orientation, which is
important for hassle-free focusing. You
don't want stars rotating in the field
of view when you're trying to focus!
Drawtube travel is 12mm and the
motion is extremely smooth and fine
– less than 1mm of travel per one full
rotation of the helical focusing ring.
Make sure your autoguider camera
is powered on and connected to your
laptop computer, and that the software
you will use for autoguiding is up and
running. Also, make sure the focus lock
thumbscrew (see Figure 5) is not tightened down. With the imaging software
set to take continuous exposures, rotate the grooved focusing adjustment ring
clockwise or counterclockwise while you watch the stars or reference numbers
(e.g., FWHM) on your laptop screen. When the stars are reasonably sharp, or
you've reached approximately the lowest FWHM, you're done!
Once focus is achieved, the focus lock thumbscrew can be lightly tightened to
ensure the drawtube remains set at that position, although this may not even be
necessary. There's no need to tighten this thumbscrew firmly since most guide
cameras are relatively lightweight, and doing so could put sideways pressure on
the drawtube that might knock your carefully set focus off a bit.
For best results we recommend focusing the guide camera at the beginning of
your imaging session, following the focusing procedures in the imaging software
you use for astrophotography, such as MaxIm DL, PHD Guiding, or Images Plus.
Focus adjustment ring
Focus lock
thumbscrew
Figure 5. Rotate the focus adjustment
ring until guide stars come into focus.
Illuminated
Plössl eyepiece
Figure 6. With the addition of an optional
Orion 12.5mm Illuminated Pössl Eyepiece,
the DMGS doubles as a crosshair
finder scope.
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