ORION TELESCOPES & BINOCULARS StarBlast AutoTracker 10140 Instruction Manual Download

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NOTE: The center ring sticker need not ever be removed
from  the  primary  mirror.  Because  it  lies  directly  in  the
shadow of the secondary mirror, its presence in no way
adversely  affects  the  optical  performance  of  the  tele-
scope  or  the  image  quality. That  might  seem  counter-
intuitive, but it’s true!

Preparing the Telescope for collimation

Once you get the hang of collimating, you will be able to do it
quickly even in the dark. For now, it is best to collimate in day-
light, preferably in a brightly lit room and aimed at a white wall.
It is recommended that the telescope tube be oriented hori-
zontally. This will prevent any parts from the secondary mirror
from falling down onto the primary mirror and causing damage
if something comes loose while you are making adjustments.
Place a sheet of white paper inside the optical tube directly
opposite the focuser. The paper will provide a bright “back-
ground” when viewing into the focuser.

Aligning the Secondary Mirror

To adjust the secondary mirror collimation, you will need to
use the included hex key.

Adjusting the Secondary Mirror’s Tilt

The tilt of the secondary mirror may occasionally require
adjustment. If the entire primary mirror reflection is not visible
in the secondary mirror when using the collimation cap, as in
Figure 5b, you will need to adjust the tilt of the secondary
mirror with the three recessed setscrews surrounding the cen-
ter screw (

Figure 6). Using the hex key, first loosen one of

the three alignment set screws by, say, one full turn, and then
tighten the other two to take up the slack. The goal is to cen-
ter the primary mirror reflection in the secondary mirror, as in
Figure 5c.

Aligning the Primary Mirror

The primary mirror of the StarBlast 114mm is fixed so no
adjustments are necessary.
The view through the collimation cap should now resemble
Figure 5c. A simple star test will indicate how well the tele-
scope optics are collimated.
Another even easier and more precise way to collimate
your reflector is to use a laser collimator such as the Orion
LaserMate II Deluxe collimator (sold separately). It comes
with complete instructions and takes no more than a couple
of minutes to achieve a dead-on collimation. We highly recom-
mend it!

Star-Testing the Telescope

When it is dark, point the telescope at a bright star and accu-
rately center it in the eyepiece’s field of view. Slowly de-focus
the image with the focusing knob. If the telescope is correct-
ly collimated, the expanding disk should be a perfect circle
(Figure 7). If the image is unsymmetrical, the scope is out of
collimation. The dark shadow cast by the secondary mirror
should appear in the very center of the out-of-focus circle, like
the hole in a donut. If the “hole” appears off-center, the tele-
scope is out of collimation.
If you try the star test and the bright star you have selected is
not accurately centered in the eyepiece, the optics will always
appear out of collimation, even though they may be perfectly
aligned. It is critical to keep the star centered, so over time you
may need to make slight corrections to the telescope’s position
in order to account for the sky’s apparent motion. A good star
to point at for a star test is Polaris, the North Star, because its
position does not move significantly over time. You can do a
star test on Polaris without even turning on power to the scope.