Orion NEWTONIAN ASTROGRAPH 9527 - Manual (Page 4)

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Using 1.25" and 2" Accessories
The 2" focuser can accommodate both 1.25" and 2" accesso-
ries, including just about any eyepiece or camera. Both the 2"
collar and removable 1.25" adapter feature a brass compres-
sion ring to hold your accessories in place without marring
their metal barrels.
The bottom of the 1.25" eyepiece adapter is threaded to
accommodate 2" Orion filters. But with a filter installed, be
careful when inserting an eyepiece or Barlow lens into the
adapter for the first time, to make sure the barrel is not long
enough to contact the filter – which could scar or crack it. If
the eyepiece or Barlow is too long, then it would be better to
thread a 1.25" filter into the barrel of the eyepiece or Barlow
itself, if it is threaded to accept one.
Fine Focus
The focuser features both coarse and fine focusing wheels.
The two large, silver-colored wheels are for coarse focus-
ing. The small black wheel next to the right-hand large focus
wheel allows ultra-precise focus adjustment at a gear ratio of
10:1, meaning ten turns of the fine focus wheel equals one
turn of the large focus wheel.
Use the large focus wheels to achieve rough focus on your
target object, then use the fine focus wheel to home in on the
exact focus point. You will be amazed at the amount of detail
that careful fine focus adjustment brings into view on targets
such as the lunar surface, planets, double stars, as well as
other celestial objects.
Attaching the Finder Scope
The included 8x50 crosshair finder scope
(Figure 3) is useful
for locating objects in the sky and centering them in the main
telescope’s field of view.
To install it, first remove the O-ring from the bracket and place
it over the body of the finder scope until it seats in the narrow
groove near the middle of the finder. Unthread the two black
nylon alignment screws on the bracket until the screw ends
are flush with the inside surface of the bracket. Slide the eye-
piece end (narrow end) of the finder scope into the end of the
bracket’s cylinder opposite the alignment screws while pull-
ing the chrome, spring-loaded tensioning pin on the bracket
with your fingers
(Figure 4). Push the finder scope through
the bracket until the O-ring seats just inside the front opening.
Release the tensioner and tighten the two black nylon screws
a couple of turns each to secure the finder scope in place.
The tips of the tensioner and nylon screws should seat into
the wide groove on the finder scope’s body.
Now slide the foot of the finder scope bracket into the dovetail
base on the main telescope. You’ll first have to back out the
thumbscrew lock on the dovetail base a few turns to allow the
bracket to slide in. Once the bracket is inserted, tighten the
thumbscrew lock.
Aligning the Finder Scope
The finder scope and the main telescope must be aligned so
they point to exactly the same spot in the sky. Alignment is
easiest to do in daylight. First, insert an eyepiece (a crosshair
eyepiece is best) into the 35mm extension adapter and insert
the adapter into the telescope’s focuser. (If you’re using a
1.25"-diameter eyepiece, you insert its barrel into the focus-
er’s 1.25" adapter, then insert that into the 35mm extension
adapter.) You’ll need the 35mm extension adapter to reach
focus with most eyepieces. Point the telescope at an object
such as the top of a telephone pole or a street sign that is at
least a quarter-mile away. Move the telescope so the target
object appears in the very center of the field of view when you
look into the eyepiece.
Now look through the finder scope. Is the object centered
in the finder scope’s field of view? If not, hopefully it will be
visible somewhere in the field of view, so that only a minor
adjustment of the finder scope’s two alignment screws will be
needed to center it. Otherwise you’ll have to make coarser
adjustments to redirect the aim of the finder scope.
Once the target object is centered on the crosshairs of the
finder scope, look again in the telescope’s eyepiece and see
if it is still centered there as well. If it isn’t, repeat the entire
process, making sure not to move the telescope while adjust-
ing the alignment of the finder scope. When the target object
Figure 4. Pull back the tensioner pin and slide the finder scope
into its bracket until the O-ring is seated in the bracket ring.
Figure 3. The 8x50 finder scope and bracket assembly.
Lock ring
O-ring
(not visible)
Tensioner
Black nylon
thumbscrews