Orion XT4.5 Instruction Manual page 7

XT4.5 during the day, before observing astronomical objects
at night. This way you will not have to fumble around trying to
orient yourself in the dark! Find a spot outdoors where you
have plenty of room to move around the telescope, and
where you have a clear view of some object or vista that is at
least 1/4-mile away. It is not critical that the base be exactly
level, but it should be placed on somewhat flat ground or
pavement to ensure smooth movement of the telescope.
Keep in mind that the SkyQuest XT4.5 was designed specif-
ically for visual observation of astronomical objects in the
night sky. Like all Dobsonians, it is not well-suited for daytime,
terrestrial usage. This is due to the inverted images the
Newtonian reflector optics provide and the low eyepiece
height when pointed near the horizon. We recommend get-
ting started during the day with the telescope, but remember
that this is not the intended use. If you find that you want to
do more daytime viewing of landscapes and vistas, you may
want to consider purchasing a spotting scope.
Remember, never point the telescope at or near the Sun
b.
a.
Figure 9:(a) Many people find the SkyQuest XT4.5 convenient to
use while sitting. (b) You can use the telescope while standing by
placing it on a sturdy table. (c) If the table is too tall, try something a
bit shorter, like a milk crate.
without using a proper solar filter over the front aperture!
Sit Down or Stand Up?
One of the great assets of the SkyQuest XT4.5 is its extreme-
ly portable size. Due to its overall short height, most adults
will find that observing while sitting on a chair or stool is most
comfortable. If wanting to stand, a sturdy table of appropriate
height will provide an adequate platform on which to place the
telescope. Other platforms, such as a milk crate, can also be
employed in order to achieve a range of eyepiece heights.
(Figure 9)
Younger children will find that the telescope is a perfect height
for them to use while standing; this is one of the reasons that
it is ideal for budding young astronomers.
Altitude and Azimuth
The Dobsonian base of the SkyQuest XT4.5 permits motion of
the telescope along two axes: altitude (up/down) and azimuth
(left/right) (see Figure 10). 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 telescope (Figure 11) and move it left
Figure 10. The SkyQuest has two axes of motion: altitude
(up/down) and azimuth (left/right).
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
gently - let it glide. In this way you can point the telescope to
any position in the night sky, from horizon to horizon.
c.
One of the unique features of the SkyQuest XT is the
Navigation Knob located underneath the telescope tube near
the open end. This knob makes for easy, smooth movement of
the telescope. You can use it to move the telescope in both the
azimuth and altitude directions.
You may find it convenient to hold your other hand near the
rear of the telescope tube to steady it while moving and aim-
ing the telescope.
Focusing the Telescope
Insert the low-power 25mm eyepiece into the focuser and
secure with the thumbscrew. Move the telescope so the front
Altitude
Azimuth
Figure 11: Try grasping
the telescope as shown
for easiest pointing. The
left hand uses the
Navigation Knob as a
"handle", while the right
hand is on the rear of
the tube.
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