Orion AstroView User manual

IN 112 Rev. C 05/02
Providing Exceptional Consumer Optical Products Since 1975
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Orion®
AstroView™ 90mm EQ
#9024 Equatorial Refracting Telescope
INSTRUCTION MANUAL

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Figure 1. AstroView 90 EQ Parts Diagram
Tube ring mounting plate
Dec. lock knob
Dec. setting circle
R.A. lock knob
R.A. slow-motion control
Counterweight lock knob
Counterweight shaft
Counterweight
Latitude locking T-bolt
Azimuth lock knob
Accessory tray bracket
attachment point
Tripod leg lock knob
Piggyback camera adapter
Tube mounting rings
Finder scope bracket
Finder scope
Alignment screws (2)
Eyepiece
Star diagonal
Focus knob
Dec. slow-motion control
R.A. setting circle
Latitude adjustment T-bolt
Accessory tray bracket
Accessory tray

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Table of Contents
1. Parts List . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Assembly . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Balancing the Telescope . . . . . . . . . . . . . 5
4. Aligning the Finder Scope . . . . . . . . . . . . 6
5. Setting Up and Using the
Equatorial Mount . . . . . . . . . . . . . . . . . . . 6
6. Using Your Telescope—
Astronomical Observing . . . . . . . . . . . . . 10
7. Astrophotography . . . . . . . . . . . . . . . . . . 13
8. Terrestrial Viewing . . . . . . . . . . . . . . . . . 14
9. Care and Maintenance . . . . . . . . . . . . . . 14
10. Specifications . . . . . . . . . . . . . . . . . . . . 14
1. Parts List
Qty. Description
1 Optical tube assembly
1 German-type equatorial mount
2 Slow-motion control cables
1 Counterweight
1 Counterweight shaft
3 Tripod legs
1 Accessory tray with mounting hardware
1 Accessory tray bracket
2 Optical tube mounting rings (located on optical tube)
1 6x30 achromatic crosshair finder scope
1 Finder scope bracket with O-ring
1 Mirror star diagonal (1.25")
1 25mm (36x) Sirius Plössl eyepiece (1.25")
1 10mm (91x) Sirius Plössl eyepiece (1.25")
1 Objective lens dust cap
4 Assembly Tools (2 wrenches, Phillips-head
screwdriver, flat-head screwdriver key)
2. Assembly
Carefully open all of the boxes in the shipping container.
Make sure all the parts listed in the parts list are present.
Save the boxes and packaging material. In the unlikely event
that you need to return the telescope, you must use the origi-
nal packaging.
Assembling the telescope for the first time should take about
30 minutes. No tools are needed other than the ones provid-
ed. All screws should be tightened securely to eliminate flex-
ing and wobbling, but be careful not to over-tighten or the
threads may strip. Refer to Figure 1 during the assembly
process.
During assembly (and anytime, for that matter), Do not touch
the surfaces of the telescope objective lens or the lenses of
the finder scope or eyepieces with your fingers. The optical
surfaces have delicate coatings on them that can easily be
damaged if touched inappropriately. Never remove any lens
assembly from its housing for any reason, or the product
warranty and return policy will be void.
1. Lay the equatorial mount on its side. Attach the tripod
legs one at a time to the mount using the screws installed
in the tops of the tripod legs. Remove the screw from the
leg, line up the holes in the top of the leg with the holes in
the base of the mount, and reinstall the screw so it pass-
es through the leg and the mount. Make sure that a
washer is between the screw head and the tripod leg and
between the wingnut and tripod leg.Tighten the wingnuts
only finger-tight, for now. Note that the accessory tray
bracket attachment point on each leg should face inward.
2. Tighten the leg lock knobs at the base of the tripod legs.
For now, keep the legs at their shortest (fully retracted)
length; you can extend them to a more desirable length
later, after the scope is completely assembled.
3. With the tripod legs now attached to the equatorial
mount, stand the tripod upright (be careful!) and spread
Congratulations on your purchase of a quality Orion telescope. Your new AstroView 90mm EQ Refractor is
designed for high-resolution viewing of astronomical objects. With its precision optics and equatorial mount, you’ll be able to
locate and enjoy hundreds of fascinating celestial denizens, including the planets, Moon, and a variety of deep-sky galaxies,
nebulas, and star clusters.
If you have never owned a telescope before, we would like to welcome you to amateur astronomy.Take some time to familiar-
ize yourself with the night sky. Learn to recognize the patterns of stars in the major constellations; a star wheel, or planisphere,
available from Orion or from your local telescope shop, will greatly help.With a little practice, a little patience, and a reasonably
dark sky away from city lights, you’ll find your telescope to be a never-ending source of wonder, exploration, and relaxation.
These instructions will help you set up, properly use, and care for your telescope. Please read them over thoroughly before
getting started.
WARNING: Never look directly at the Sun
through your telescope or its finder scope—even
for an instant—without a professionally made
solar filter that completely covers the front of the
instrument, or permanent eye damage could
result.Young children should use this telescope
only with adult supervision.

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2. Loosen the latitude locking T-bolt.Turn the latitude adjust-
ing T-bolt and tilt the mount until the pointer on the lati-
tude scale is set at the latitude of your observing site. If
you don’t know your latitude, consult a geographical atlas
to find it. For example, if your latitude is 35° North, set the
pointer to +35. Then retighten the latitude locking T-bolt.
The latitude setting should not have to be adjusted again
unless you move to a different viewing location some dis-
tance away.
3. Loosen the Dec. lock knob and rotate the telescope opti-
cal tube until it is parallel with the R.A. axis. The pointer
on the Dec. setting circle should read 90°. Retighten the
Dec. lock knob.
4. Loosen the azimuth lock knob and rotate the entire equa-
torial mount left-to-right so the telescope tube (and R.A.
axis) points roughly at Polaris. If you cannot see Polaris
directly from your observing site, consult a compass and
rotate the equatorial mount so the telescope points
North. Retighten the azimuth lock knob.
The equatorial mount is now approximately polar-aligned for
casual observing. More precise polar alignment is required
for astrophotography. Several methods exist and are
described in many amateur astronomy reference books and
astronomy magazines.
Note: From this point on in your observing session, you
should not make any further adjustments in the azimuth
or the latitude of the mount, nor should you move the
tripod. Doing so will undo the polar alignment. The tele-
scope should be moved only about its R.A. and Dec.
axes.
Use of the R.A. and Dec.
Slow-Motion Control Cables
The R.A. and Dec. slow-motion control cables allow fine
adjustment of the telescope’s position to center objects with-
in the field of view. Before you can use the cables, you must
manually “slew” the mount to point the telescope in the vicini-
ty of the desired target. Do this by loosening the R.A. and
Dec. lock knobs and moving the telescope about the mount’s
R.A. and Dec. axes. Once the telescope is pointed some-
where close to the object to be viewed, retighten the mount’s
R.A. and Dec. lock knobs.
The object should now be visible somewhere in the tele-
scope’s finder scope. If it isn’t, use the slow-motion controls
to scan the surrounding area of sky. When the object is visi-
ble in the finder scope, use the slow-motion controls to cen-
ter it. Now, look in the telescope with a long focal length (low
magnification) eyepiece. If the finder scope is properly
aligned, the object should be visible somewhere in the field
of view.
Once the object is visible in the telescope’s eyepiece, use
the slow-motion controls to center it in the field of view. You
can now switch to a higher magnification eyepiece, if you
Figure 4. The equatorial mount.
R.A. lock knob
RRIIGGHHTTAASSCCEENNSSIIOONNAAXXIISS
Declination (Dec.)
slow motion control
Latitude adjustment T-bolt
Azimuth lock knob
Declination (Dec.)
setting circle
Right ascension
(R.A.) setting circle
Right ascension (R.A.)
slow motion control
Latitude locking T-bolt
Latitude scale
DECLINATIONAXIS
Figure 5. To find Polaris in the night sky, look north and find the
Big Dipper. Extend an imaginary line from the two “Pointer Stars” in
the bowl of the Big Dipper. Go about five times the distance
between those stars and you’ll reach Polaris, which lies within 1° of
the north celestial pole (NCP).
Big Dipper
(in Ursa Major)
Little Dipper
(in Ursa Minor)
N.C.P.
PointerStars
Cassiopeia
Polaris