Orion SKYQUEST XT8 - Manual (Page 12)

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the base with one hand while supporting the telescope tube
vertically with the other (Figure 17). Now, lift the telescope by
the handle. Once the telescope is in the horizontal position,
you can carry the entire unit with one hand while supporting
the optical tube with the other hand.
If you wish to carry the optical tube and base separately, sim-
ply unthread the retaining and tensioning knobs until they are
free of the base and optical tube (make certain the spacer
does not fall off the retaining knob). Lift the tube off the base,
then rethread the knobs back into the bearings so that you
do not lose them. Be careful, however, not to bend the knobs
when transporting the telescope tube. Do not use the naviga-
tion knob as a carry handle! It is not designed to support the
weight of the telescope tube and could break off or damage
the tube.
Note: The SkyQuest may be too heavy for some users to
lift and carry as one unit. Do not strain yourself! If the load
seems too heavy, carry the base and tube separately.
When putting the SkyQuest into a vehicle, common sense
prevails. It is especially important that the optical tube does
not get knocked around; this can cause the optics to become
misaligned, and could dent the tube. We recommend trans-
porting and storing the tube assembly in an optional padded
case for proper protection.
4. alignment (collimation)
of the optical system
To get the sharpest images, your telescope’s optical system
must be in precise alignment. The process of aligning the
primary and secondary mirrors with each other and with the
mechanical axis of the telescope is called collimation.
Your telescope’s optical system was collimated at the fac-
tory and will probably not need any further adjustment. But
rough handling during shipment can knock the optics out
of alignment, in which case you will need to recollimate the
system. Collimation is relatively easy to do and can be done
in daylight. It is a good idea to check the collimation of your
telescope before each observing session and make any nec-
essary adjustments.
To check collimation, remove the eyepiece and look down the
focuser drawtube. You should see the secondary mirror cen-
tered in the drawtube, as well as the reflection of the primary
mirror centered in the secondary mirror, and the reflection of
the secondary mirror (and your eye) centered in the reflection
of the primary mirror, as depicted in Figure 18a. If anything
is off-center, as in Figure 18b, proceed with the following col-
limation procedure.
Figure 18. Collimating the optics. (a) When the mirrors are properly aligned, the view down the focuser drawtube should
look like this. (b) With the collimation cap in place, if the optics are out of alignment, the view might look something like this.
(c) Here, the secondary mirror is centered under the focuser, but it needs to be adjusted (tilted) so that the entire primary
mirror is visible. (d) The secondary mirror is correctly aligned, but the primary mirror still needs adjustment. When the primary
mirror is correctly aligned, the “dot” will be centered, as in (e) .
a.
e. d.
c. b.
Note: 10" model has 4 mirror clips