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Altitude
Azimuth
Figure 8.
The SkyQuest has two axes of motion: altitude (up/
down) and azimuth (left/right).
2" eyepiece adapter
Focus knobs
Figure 9.
The 2" Crayford focuser (XT8 and XT10)
Remember, never point the telescope at or
near the Sun without using a proper solar filter
over the front aperture!
Altitude and Azimuth
The Dobsonian base of the SkyQuest permits motion of the
telescope along two axes: altitude (up/down) and azimuth
(left/right) (Figure 8). This is very convenient, since up/down
and left/right are the most "natural" ways that people aim. As a
result, pointing the telescope is exceptionally easy.
Simply take hold of the end of the tube and move it left or
right so the base rotates about its central azimuth bolt, and
move it up or down so the altitude side bearings rotate in the
base's cradle. Both motions can be made simultaneously and
in a continuous manner for easy aiming. Move the telescope
1.25" eyepiece
adapter
Focus lock
thumbscrew
Tension adjustment screw
Naked-eye view
View through and telescope
Figure 10.
The view through a reflector telescope is upside
down.
gently—let it glide. In this way you can point the telescope to
any position in the night sky, from horizon to horizon.
Focusing the Telescope
Insert the 25mm eyepiece into the focuser and secure with the
thumbscrew(s). Move the telescope so the front (open) end is
pointing in the general direction of an object at least 1/4-mile
away. Now, with your fingers, slowly rotate one of the focusing
knobs until the object comes into sharp focus. Go a little bit
beyond sharp focus until the image just starts to blur again,
then reverse the rotation of the knob, just to make sure you've
hit the exact focus point.
If you have trouble focusing, rotate the focusing knob so the
drawtube is in as far as it will go. Now look through the eye-
piece while slowly rotating the focusing knob in the opposite
direction. You should soon see the point at which focus is
reached.
The 2" Crayford focuser of the XT8 and XT10 models features
a thumb screw on the bottom of the focuser body (Figure 9)
which will lock the focuser drawtube in place once the tele-
scope is properly focused.
If you find the drawtube tension when focusing is either too
tight (focus knob is difficult to turn) or too loose (image shifts
when focusing or drawtube moves inward by itself), the ten-
sion can be adjusted for optimal performance. On the XT8 &
XT10, the focusing tension adjustment set screw is a 3mm
socket head set screw located below the focus lock thumb
screw (Figure 9). A 3mm hex key is required for adjustment
of focus tension. Due to the rack-and-pinion focuser design on
the XT6, tension adjustment should not normally be needed
as it has been pre-adjusted at the factory.
Note: The image in the main telescope will appear upside-
down (rotated 180°). This is normal for reflector telescopes
(see Figure 10).
7
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