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When putting the SkyQuest into a vehicle, common sense
prevails. It is especially important that the optical tube does
not knock around; this can cause the optics to become mis-
aligned, and could dent the tube. We recommend
transporting and storing the tube assembly in a padded case
for proper protection.
4. Collimation
(Aligning The Mirrors)
Collimation is the process of adjusting the mirrors so they are
perfectly aligned with one another.Your telescope’s optics were
aligned at the factory, and should not need much adjustment
unless the telescope was handled roughly during shipment.
Accurate alignment is important to ensure the peak perform-
ance of your telescope, so it should be checked regularly.
Collimation is relatively easy to do and can be done in daylight.
To check the collimation, remove the eyepiece and look down the
focuser drawtube.You should see the secondary mirror centered
in the drawtube as well as the reflection of the primary mirror
centered in the secondary mirror, and the reflection of the sec-
ondary mirror (and your eye) centered in the reflection of the
primary mirror, as in Figure 14a. If anything is off-center, as in
Figure 14b, proceed with the following the collimation procedure.
It helps to put a piece of white paper on the inside of the optical
tube opposite the focuser. It forms a bright background behind
the secondary mirror, making it easier to distinguish the mirror
holder from the background.
Use a Collimating Tool
To aid in centering your line of sight down the focuser drawtube,
and in centering the mirror reflections during collimation, it is very
helpful to use a precision collimating tool containing crosshairs,
such as the Orion Collimating Eyepiece (#3640). We strongly
recommend that you purchase one.
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. The film canister
collimating tool goes into the focuser like an eyepiece, with the
bottom end out.
Aligning the Secondary Mirror
With eyepiece removed, look straight down the open focuser
drawtube at the secondary (diagonal) mirror. Ignore the
Figure 14. Collimating the optics. (a) When the mirrors are properly aligned, the view down the focuser drawtube should look like this. (b) 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 eye will be centered, as in (a).
a.
b.
c.
d.
