Orion 9527 User Manual

INSTRUCTION MANUAL

Orion® 8" f/4.0

Newtonian Astrograph

#9527

Providing Exceptional Consumer Optical Products Since 1975

OrionTelescopes.com

Customer Support [phone] • E-mail: [e-mail]

Corporate Offices [phone] • 89 Hangar Way, Watsonville, CA 95076

IN 378 Rev. A 1/10

8x50 Finder
scope

Finder scope
bracket

Primary mirror cell

Dovetail
finder scope
base

Figure 1.

Secondary
mirror “spider”

Focus
wheel

The 8" f/4.0 Newtonian Astrograph

DETAIL

Focus wheel

Drawtube
tensioning
thumbscrew

Congratulations on your purchase of an Orion® 8"
f/4.0 Newtonian Astrograph. It features fast, high-

quality parabolic optics; a machined, dual-speed
Crayford focuser with linear-track bearing; and
excellent mechanical construction. This telescope
has been specially optimized for astrophotography
with DSLR and astronomical CCD imaging cam­eras. These instructions will help you set up and
use your telescope.

Parts List

Optical Tube Assembly

Optical tube dust cover

1.25" eyepiece adapter

8x50 finder scope with bracket

Pair of hinged tube rings

35mm extension tube adapter

Collimation cap

Battery holder for cooling fan

Focuser

Tube rings

Fine focus
wheel

1.25" Adapter

2" Accessory
collar

Focus lock
thumbscrew

DETAIL

Getting Started

Your 8" f/4.0 Newtonian Astrograph arrives nearly fully
assembled from the factory. The optics were collimated at the
factory, however you should check the collimation prior to first
use to make sure it held during shipment (see “Collimating
the Optics”). Not uncommonly, a minor adjustment may be
necessary.

We recommend keeping all of the original packaging. In the
unlikely event you should need to ship the telescope back to
Orion for warranty repair service, you should use the original
packaging to ensure the telescope stays intact during ship­ping. Take a moment to inspect the telescope and all of its
parts.

Before proceeding with the instructions, refer to Figure 1 to
familiarize yourself with some of the features and components
of the telescope.

Connecting the Telescope to a Mount

The 8" f/4.0 Newtonian Astrograph comes with a pair of
hinged, felt-lined tube rings to hold the optical tube assembly.
Each ring has a flat boss on opposite sides. One boss has a
single M6 metric threaded hole. The other has three holes;
the center hole has a ¼"-20 thread and the two flanking holes

2

1.25" Adapter

Focus lock thumbscrew

Accessory lock
thumbscrew

Accessory lock
thumbscrew

Brass
compression ring

Coarse
focus wheel

Figure 2.

2" Collar

Accessory
lock
thumbscrew

10:1 Fine
focus wheel

Drawtube tensioning
thumbscrew

Coarse
focus wheel

The dual-speed 2" Crayford-type linear bearing focuser

are M6. It is likely that only the center hole will be needed to
attach the rings to a dovetail plate for your mount or for your
guide scope assembly.

Balancing the 8" f/4.0 Newtonian Astrograph is achieved
by sliding the dovetail mounting plate (sold separately) for­ward or backward within the mount’s dovetail saddle. You
can also move the telescope forward or backward within the
tube rings. The tube rings offer the most adjustment range.
Loosen the tube ring clamps slightly and slide the telescope
tube forward or backward as needed to reach optimum bal­ance, then retighten the tube ring clamps. Rotating the tele­scope to achieve a comfortable eyepiece or camera angle is
done in the same fashion. Simply loosen the tube ring clamps
just enough to allow the optical tube to rotate within the tube
rings. Retighten the tube ring clamps securely once you have
reached the desired eyepiece or camera orientation.

Dual-Speed Crayford Focuser with Linear
Track Bearing

The 8" f/4.0 Newtonian Astrograph features a machined alu­minum, 2" dual-speed Crayford-type focuser (Figure 2) that
incorporates a linear track bearing design. The linear bear­ing eliminates drawtube play and enables support of heavier
loads without slippage. If the drawtube does slip under the
weight of your imaging system or heavy visual accessories,
simply increase the drawtube tension by gently tightening the
drawtube tensioning thumbscrew as needed.

The smooth focus motion and fine-focus wheel allow preci­sion adjustments for critical focusing of eyepieces and camer­as. Once you have reached focus, you can lock the drawtube
in place by tightening the focus lock thumbscrew.

The focuser drawtube has 50mm of travel and English and
metric hash marks, which allow you to note the drawtube
position at the precise focus point so you can return to it when
you need to.

3

Lock ring

O-ring
(not visible)

Tensioner

Black nylon
thumbscrews

Figure 3. The 8x50 finder scope and bracket assembly.

Using 1.25" and 2" Accessories

The 2" focuser can accommodate both 1.25" and 2" accesso­ries, including just about any eyepiece or camera. Both the 2"
collar and removable 1.25" adapter feature a brass compres­sion 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 focus­ing. 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 eye­piece end (narrow end) of the finder scope into the end of the

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.

bracket’s cylinder opposite the alignment screws while pull­ing 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 focus­er’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 adjust­ing the alignment of the finder scope. When the target object

4