Orion SIRIUS 9995 - Manual (Page 22)

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8. Without moving the R.A. axis, adjust the azimuth control
knobs (Figure 2) to orient Polaris in the center of the eye-
piece field of view. Adjustment in Dec. axis using the hand
controller may be necessary.
9. Loosen the R.A. lock knob and carefully rotate the tele-
scope 180° about the R.A. axis (Figure 17a &17b) This
should be done as accurately as possible referencing the
R.A. mechanical setting circle.
10.Adjust the position of the telescope in the Dec. axis so
Polaris lies on the R.A. crosshairs of the illuminated reticle
eyepiece (Figure 16).
11.Carefully push the telescope in a horizontal motion while
observing the movement of Polaris in the eyepiece field of
view (Figure 18). This will determine which direction (left
or right) moves Polaris closer to the center of the eyepiece
field of view.
12.Carefully and gently loosen both the tube ring attachment
screws (Figure 3) by a couple of turns.
13.Make adjustments to the optical axis offset adjustment
screws (the socket head cap screws located at each cor-
ner of the mounting plate, see Figure 3) according to the
results of step 11. If Polaris moves toward the center when
the telescope is pushed as indicated in Figure 18, loosen
the adjustment screws near the front of the tube and tight-
en the adjustment screws closer to the back of the tube
(Figure 19a). If Polaris moves away from the center when
the telescope is pushed as in Figure 18, loosen the adjust-
ment screws near the back of the tube and tighten the
adjustment screws closer to the front of the tube (Figure
19b). Look into the eyepiece. Adjust the adjustment screws
just enough to place Polaris HALF the distance back to the
center of the illuminated reticle eyepiece (Figure 20).
14.Repeat steps 7 to 12 until Polaris remains in the center
of the eyepiece field of view, or moves slightly around the
center, when the mount is rotated about the R.A. axis.
15. Retighten both the tube ring attachment screws.
Note: This calibration method can be applied to both refract-
ing and reflecting telescope designs. Differences in the optical
path of telescopes do not affect how the telescope tube and
tube rings should be adjusted on the mounting plate.
Figure 18. Gently push the telescope horizontally to determine
direction of optical axis offset.
Figure 17a‑b. Rotate the telescope 180° about the R.A.axis.
a.
b.