Celestron STARSENSE EXPLORER 8 DOBSONIAN Manuel D'instructions page 16

For the 10" and 12" Dobsonians, you won't need
any tools to tilt the primary mirror. Instead, simply adjust
the thumbscrews. Three of the thumbscrews are locking
screws, while the other three thumbscrews adjust the tilt.
a. Start by loosening all three of the locking
thumbscrews (Figure 21).
LOCKING
THUMBSCREWS
Figure 21: For the 10" and 12" Dobs, there are three spring-loaded
collimation thumbscrews that adjust the tilt of the primary mirror. The
other three thumbscrews lock the mirror in place once tilt adjustments are
completed.
b. Adjust the collimation thumbscrews one at a time.
Each collimation thumbscrew is spring-loaded, so
you can rotate it clockwise or counterclockwise.
c. Continue adjusting the screws until the refl ection
of the secondary mirror is centered within the
refl ection of the primary mirror.
16 I ENGLISH
10
INCH DOB
LOCKING
THUMBSCREWS
12
INCH DOB
d. Re-tighten the three locking thumbscrews until
snug.
e. When you are fi nished, the view through the
collimation cap should look like Figure 16.
Your telescope's optics are now aligned and ready for use.
You can also confi rm a telescope's alignment at night by
pointing the telescope at a bright star at high magnifi cation.
Center the star in the fi eld of view and slightly defocus the
star—it should appear like a circle with a hole in the middle.
(The "hole" is the shadow from the secondary mirror.) If the
hole is not centered within the circle, you'll need to make
additional adjustments to collimation (Figure 22).
GOOD COLLIMATION
Figure 22: You can check collimation by defocusing a bright star centered
in the fi eld of view and checking to see if the "hole" is centered. If it is not
centered, some adjustment is needed.
TRANSPORTING
Transporting the StarSense Explorer Dobsonian is easy,
especially considering its size. First, remove the telescope
tube from the base by loosening the altitude tensioning
knob and lifting the telescope tube. You can carry the tube
and the base separately by their integrated carry handles.
The handles are positioned to balance the load, so neither
component should be awkward to carry.
The 12" Dob optical tube weighs nearly 50 lbs. so make
sure to bend your knees when lifting and do not overexert
yourself! If it is too heavy for you to carry alone, we
recommend having another person assist.
NEEDS ADJUSTMENT