Collimating is the process of aligning a telescope’s optics.
Your StarMax or Apex’s primary mirror was aligned at the
factory and should not need adjustment unless the telescope
is handled roughly. This manual contains information on how
to test the collimation of your telescope and instructions for
proper alignment should that be needed.
Star-Testing the Telescope
Before you start adjusting the primary mirror of your telescope, make certain that it is actually out of collimation by
performing a star test.
Take your telescope out at dusk and let it acclimate to the
outside temperature; this usually takes 30-60 minutes.When
it is dark, point the telescope upwards at a bright star and
accurately center it in the eyepiece’s field of view.Slowly de-
focus the image with the focusing knob. If the telescope is
correctly collimated, the expanding disk should be a circle
(Figure 1). If the image is unsymmetrical, the scope is out of
collimation.Also , 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
telescope is out of collimation.
If you try the star test but 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 will need to make slight corrections to the telescope’s position in order to account for the sky’s apparent
motion.
Collimating the StarMax/Apex
To collimate your telescope, remove the diagonal and eyepiece and look into rear opening of the tube (also remove the
dust cover from the front of the tube). This should be done
indoors, with the telescope pointed at a white wall in a welllit room. Try to keep your eye centered with respect to the
rear opening of the tube as best as possible.Using an Orion
Collimating Eyepiece will aid greatly in keeping your e y e centered and is strongly recommend.
Alternatively, you can make a crude collimating tool out of an
empty, black plastic 35mm film canister. It will not have
crosshairs, so it won’t be as precise, but it will be better than
nothing. Cut 1/2" from the top lip of the canister and put a
1/16" to 1/8" diameter hole in the center of its bottom. Inser t
the film canister collimating tool into the focuser like an eyepiece with the bottom end out.
Collimating Orion StarMax™and Apex
™
Maksutov-Cassegrain Telescopes
(StarMax 90,102, and 127, Apex 90, 102, and 127)
(9821,9824,9826,9820,9823,9825)
Figure 1: A star test will determine if a telescope’s optics are
properly collimated. An unfocused view of a bright star through the
eyepiece should appear as illustrated on right if optics are perfectly
collimated. If circle is unsymmetrical, as in illustration on left, scope
needs collimation.
IN 183 Rev A 03/02
Out of collimation Collimated
Once you are ready to collimate, look into rear opening of the
tube. If your telescope is out of collimation, it will resemble
Figure 2a, a properly collimated scope will resemble Figure
2b.The direction of the misalignment in your telescope may
differ from Figure 2a, but the diagram will give you the general idea of how things will look.
Note there are six alignment screws on the back of the optical tube, three large and three small.You will need 3mm and
2mm Allen wrenches to turn these screws.These alignment
screws push and pull the mirror cell in order to tilt it. When
you loosen or tighten one of these screws, the other five
screws must be adjusted as well to keep the proper amount
of pressure on the back of the mirror cell. By making slight
adjustments to how much the screws are tightened and loosened, you will change the alignment of the primary mirror.
Look into the rear opening of the tube and locate the black
crescent that shows the telescope is out of alignment.
(Figure 2a). Note which way the front of the telescope would
need to move in order to “fill”that black crescent and resemble Figure 2b.Then look at the back end of the telescope and
locate the alignment screw that is in the direction that the
front of the telescope needs to move.For example, if the view
in your telescope resembled Figure 2a, then you would want
to move the front opening of the telescope scope to the right.
Then the alignment screw you would start with would be the
screw on the right as shown in Figure 3.
Your actions now depend on whether this alignment screw is
a small or large screw. Please note that you will be working
to adjust the mirror cell by keeping all the screws not too
loose and not too tight. Follow the steps listed below carefully and refer to the figures that accompany them.
2
Figure 2a: If the telescope’s optics are out of alignment the
view through the rear opening of the telescope will resemble
Figure 2a.
Figure 2b: With the optics properly aligned the view through the
rear opening of the telescope will resemble Figure 2b.
Front of
Figure 3: If the view through
the rear opening of the telescope
resembled Figure 2a, then the
alignment screw you would start
with would be this one.The
actual first alignment screw you
would pick will vary depending on
which way the front opening
would need to move in order to
“fill” the black crescent.
Figure 2a Figure 2b
Figure 3
telescope
Secondary
mirror
Reflection of
your eye in
secondary
mirror
Front of
telescope
Secondary
mirror
Reflection of
your eye in
secondary
mirror
Secondary
reflection of
inside of tube
Reflection of
inside of tube
(misalignment)
If the alignment screw is a large screw
First, using the 3mm Allen wrench, turn the large screw clockwise a small amount, no more than a 1/4 turn. (Figure 4a)
Now, with the 2mm Allen wrench turn the two adjacent small
screws (Figure 4b) counterclockwise no more than 1/4 tur n.
Locate the small screw that is 180° opposite the first screw
(Figure 4c) and turn it clockwise no more than 1/4 turn.
Turn the two large screws adjacent to the small screw
(Figure 4d) counterclockwise no more than 1/4 turn.
Repeat the above steps until the front opening is centered in
the direction you wanted it to go.You may need to repeat this
(or the small screw adjustment process) with other screws in
order to align it in other directions.
3
Figure 4c: Turn the small
screw that is 180° opposite
the first screw clockwise no
more than 1/4 turn.
Figure 4d: Turn the two
large screws adjacent to the
small screw counterclockwise
no more than 1/4 turn.
Figure 4a: Using the 3mm
Allen wrench, turn the large
screw clockwise a small
amount, no more than 1/4 of
a turn. (Note, actual selected
alignment screw will vary.)
Figure 4b: Now, with the
2mm Allen wrench, turn the
two adjacent small screws
counterclockwise no more
than 1/4 turn.
If the alignment screw is a small screw
First, using the 2mm Allen wrench, turn the small screw
counterclockwise a small amount, no more than a 1/4 turn.
(Figure 5a)
Now , with the 3mm Allen wrench, turn the two adjacent large
screws (Figure 5b) clockwise no more than 1/4 turn.
Locate the large screw that is 180° opposite the first screw
(Figure 5c) and turn it counterclockwise no more than 1/4 turn.
Turn the two small screws adjacent to the large screw (Figure
5d) clockwise no more than 1/4 turn.
Repeat the above steps until the front opening is centered in
the direction you wanted it to go.You may need to repeat this
(or the large screw adjustment process) with other screws in
order to align it in other directions.
Repeat these two procedures as needed until the view
through the scope resembles Figure 2b.
Finishing Collimation
Once you have finished adjusting your telescope, you will
need to perform another star test (described earlier) to check
the collimation. If your telescope appears collimated after
star testing, it should not need adjustment again unless it is
roughly handled.
If you have gone through this process and your telescope is
still out of collimation, please contact Orion customer support.Y ou ma y need to return the telescope for repair (cov ered
on warranty for 1 year after purchase).
Figure 5a: Using the 2mm
Allen wrench, turn the large
screw counterclockwise a small
amount, no more than 1/4 of a
turn. (Note: Actual selected
alignment screw will vary.)
Figure 5b: Now, with the
3mm Allen wrench turn the
two adjacent large screws
clockwise no more than
1/4 turn.
Figure 5c: Turn the
large screw that is 180°
opposite the first screw
counterclockwise no more
than 1/4 tur n.
Figure 5d: Turn the two
large screws adjacent to the
small screw clockwise no
more than 1/4 turn.
Figure 4a Figure 4c
Figure
4b
Figure 4d
Figure 5a Figure 5c
Figure 5b
Figure 5d
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