Instruction manual
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4. Use the hand control buttons to move the de-focused star
image to the edge of the eld of view, in the same direction that
the central obstruction of the star image is skewed.
5. While looking through the eyepiece, use a screw driver to
turn the collimation screw you located in step 2 and 3. Usually
a tenth of a turn is enough to notice a change in collimation. If
the star image moves out of the eld of view in the direction
that the central shadow is skewed, than you are turning the
collimation screw the wrong way. Turn the screw in the opposite
direction, so that the star image is moving towards the center of
the eld of view.
6. If while turning you notice that the screws get very loose,
then simply tighten the other two screws by the same amount.
Conversely, if the collimation screw gets too tight, then loosen
the other two screws by the same amount.
7. Once the star image is in the center of the eld of view,
check to see if the rings are concentric. If the central obstruction
is still skewed in the same direction, then continue turning the
screw(s) in the same direction. If you nd that the ring pattern
is skewed in a dierent direction, than simply repeat steps 2
through 6 as described above for the new direction.
Perfect collimation will yield a star image very symmetrical just
inside and outside of focus. In addition, perfect collimation
delivers the optimal optical performance specications that your
telescope is built to achieve.
If seeing (i.e., air steadiness) is turbulent, collimation is dicult
to judge. Wait until a better night if it is turbulent or aim to a
steadier part of the sky. A steadier part of the sky is judged by
steady versus twinkling stars.
FIGURE 6-3
A collimated telescope should appear symmetrical
with the central obstruction centered in the star’s
diraction pattern.