ORION TELESCOPES & BINOCULARS SkyView Pro 100 EQ 9864 Instruction Manual

INSTRUCTION MANUAL

IN 190 Rev. A 09/02

Providing Exceptional Consumer Optical Products Since 1975

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

Corporate Offices [phone]
P.O. Box 1815, Santa Cruz, CA 95061

Orion

®

SkyView

™

Pro 100 EQ

#9864 Equatorial Refractor Telescope

2

Figure 1. The SkyView Pro 100 EQ.

Declination lock lever
(opposite side)

Right Ascension lock lever
(opposite side)

Declination slow-motion
control knob

Safety thumbscrew
Mounting plate securing knob

Counterweight shaft
Counterweight
Counterweight lock knob

Tube rings
Finder scope
Finder scope bracket

Eyepiece

90° Star Diagonal
Focus wheel
Right Ascension

slow-motion control knob
Latitude scale
Latitude adjustment L-bolts

Center support shaft

Tripod support tray

Tripod leg

Leg lock knobs

Objective lens

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Table of Contents

1. Unpacking . . . . . . . . . . . . . . . . . . . . . . . 3

2. Parts List . . . . . . . . . . . . . . . . . . . . . . . . 3

3. Assembly . . . . . . . . . . . . . . . . . . . . . . . . 3

4. Balancing the Telescope . . . . . . . . . . . . 5

5. Using Your Telescope . . . . . . . . . . . . . . . 5

6. Setting Up and Using

the Equatorial Mount . . . . . . . . . . . . . . . 7

7. Astronomical Observing . . . . . . . . . . . . 12

8. Terrestrial Observing . . . . . . . . . . . . . . 15

9. Astrophotography . . . . . . . . . . . . . . . . . 15

10. Collimating (Aligning the Optics) . . . . . 16

11. Care and Maintenance . . . . . . . . . . . . . 17

12. Specifications . . . . . . . . . . . . . . . . . . . . 17

1. Unpacking

The SkyView Pro 100 EQ will arrive in one box. Be careful
unpacking the box.We recommend keeping the box and all
original packaging.In the event that the telescope needs to be
shipped to another location, or returned to Orion for warranty
repair, having the proper box and packaging will help ensure
that your mount will survive the journey intact.

Make sure all the parts in the Parts List are present. Be sure
to check each interior box carefully, as some parts are
small. If anything appears to be missing or broken, immedi­ately call Orion Customer Support (800-676-1343) or email
[e-mail] for assistance.

2. Parts List

1 Tripod
1 Equatorial mount
1 Tripod support tray
1 Counterweight shaft
1 Counterweight
2 Slow-motion control knobs
1 R.A. axis rear cover
1 Latitude adjustment L-bolt
1 Optical tube assembly
2 Tube rings with mounting screws
1 Tube ring mounting plate
1 25mm Sirius Plössl eyepiece
1 10mm Sirius Plössl eyepiece
1 90° Star diagonal
1 Finder scope
1 Finder scope bracket with O-ring
1 Dust Cover
1 Collimation tool

3. Assembly

Assembling the telescope for the first time should take about
30 minutes. No tools are needed other than the ones provid­ed.All screws should be tightened securely, 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 lenses of the telescope, 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 voided.

1. Stand the tripod legs upright and spread the legs out as far
as they will go.Keep the tripod legs at their shortest (fully
retracted) length, for now;you can extend them to a more
desirable length later, after the scope is fully assembled.

2. Place the base of the equatorial mount into the tripod
head. Orient the equator ial mount so that the post on the

Congratulations on your purchase of an Orion telescope.Your new SkyView Pro 100 EQ is designed for

high-resolution viewing and astrophotography of astronomical objects.With its precision optics and stur­dy equatorial mount, you’ll be able to enjoy hundreds of fascinating celestial denizens.

These instructions will help you set up, properly use, and care f or 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.

®

tripod head lines up with the azimuth adjustment knobs on
the equatorial mount (Figure 2).You may need to loosen
the azimuth adjustment knobs on the equatorial mount in
order to fit the mount onto the tripod head.

3. Thread the central support shaft into the equatorial mount
until tight.This will secure the equatorial mount to the tri­pod head.

4. Remove the knob and washer from the bottom of the cen­ter support shaft. Slide the tripod support tray up the bot­tom of the central support shaft until the three tray arms
are touching the legs of the tripod. The flat side of the
accessory tray should be facing up.Make sure the “V” of
each tray arm is against a tripod leg. Place the washer
back on the center support shaft against the tray, and
thread the securing knob all the way up the center support
shaft until it is tight against the tray. The tripod support tray
provides additional stability for the tripod, and holds five

1.25" eyepieces and two 2" eyepieces.

5. Thread the latitude adjustment L-bolt into the rear of the
equatorial mount as shown in Figure 1.

6. Thread the counterweight shaft into the equatorial mount
at the base of the declination axis until tight.Make sure the
casting at the top of the shaft is threaded clockwise as far
as it will go before attaching the shaft. Once the shaft is
installed, turn the casting counter-clockwise until the top of
the casting is flush with the mount.

7. Remove the knurled “toe saver”retaining screw on the bot­tom of the counterweight shaft and slide the counterweight
onto the shaft. Make sure the counterweight lock knob is
adequately loosened to allow the counterweight shaft to
pass through the hole. Position the counterweight about
halfway up the shaft and tighten the lock knobs. Replace
the toe saver at the end of the bar.The toe saver prevents
the counterweight from falling on your foot if the lock knob
happens to come loose.

8. Attach the slow-motion control knobs to the right ascen­sion and declination worm gear shafts of the equatorial

mount by sliding them onto the shafts.Line up the flat on
the end of the shaft with the corresponding feature on the
interior of the knob to attach them properly.The knobs can
be attached to either end of the shafts; use whichever end
is most convenient.

9. Attach the tube mounting r ings to the tube mounting plate
using the attachment screws that are on the tube rings.
The screws should go through the holes on the outer ends
of the mounting plate and rethread into the tube rings.
Note that the side of the mounting plate with the central
“groove” will be facing up.Use the small wrench to secure
the tube rings to the mounting plate.

10.Loosen the black mounting plate securing knob as well as
the metal safety thumbscrew on the top of the equatorial
mount. Place the mounting plate, with the tube rings
atached, in the dovetail slot on top of the equatorial mount.
Position the mounting plate so that it is centered on the
dovetail slot.Re-tighten the mounting plate securing knob
until the mounting plate is secure.Then, tighten the safety
thumbscrew. The safety thumbscrew will ensure that the
mounting plate (and telescope tube) will not fall off the EQ
mount if the mounting plate securing knob should come
loose.

Figure 2. Orient the equatorial mount so that the post on the

tripod head lines up between the azimuth adjustment knobs on the
equatorial mount.

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Post

Azimuth
adjustment
knobs

Finder scope

Finder scope bracket Nylon

alignment
thumbscrews
(2)

Focus lock ring

Figure 3b. Pull back on

the tensioner and slide the
finder scope into its bracket
until the O-ring is seated in
the bracket ring.

Figure 3a. The 6x30 finder scope.

Tensioner

11.Lay the telescope optical tube in the tube rings at about
the midpoint of the tube’s length. Center the 1/4"-20
mounting block on the optical tube relative to the tube
rings. Rotate the optical tube so that the focus wheels are
pointed down. Close the rings over the tube and tighten
the knurled ring clamps finger-tight to secure the telescope
in position.

Installing the Finder Scope

To place the finder scope (Figure 3a) in the finder scope
bracket, unthread the two black nylon screws until the screw
ends are flush with the inside diameter of the bracket.Place
the O-ring that comes on the base of the bracket over the
body of the finder scope until it seats into the slot on the mid­dle of the finder scope.Slide the eyepiece end (narrow end) of
the finder scope into the end of the bracket’s cylinder opposite
the adjustment screws while pulling the chrome, spring­loaded tensioner on the bracket with your fingers (Figure 3b).
Push the finder scope through the bracket until the O-ring
seats just inside the front opening of the bracket cylinder.
Release the tensioner and tighten the two black nylon screws
a couple of turns each to secure the finder scope in place.
Insert the base of the finder scope bracket into the dovetail
holder on the top of the focuser. Lock the bracket into position
by tightening the knurled thumbscrew on the dovetail holder.

Inserting the Diagonal and Eyepiece

Loosen the thumbscrew on the 1.25" adapter on the focuser
and remove the small dust cap.Insert the chrome barrel of the
star diagonal into the focuser and secure with the thumb­screw. Loosen the thumbscrews on the diagonal and insert
the 25mm eyepiece into the focuser and secure it with the
thumbscrews.

Your telescope is now completely assembled and should
appear as shown in Figure 1.

4. Balancing the Telescope

To ensure smooth movement of the telescope on both axes of
the equatorial mount, it is imperative that the optical tube is
properly balanced.

1. Keeping one hand on the telescope optical tube, loosen
the R.A.lock lever.Make sure the Dec.lock lever is locked.
The telescope should now be able to rotate freely about
the right ascension axis. Rotate it until the counterweight
shaft is parallel to the ground (i.e., horizontal).

2. Now loosen the counterweight lock knob and slide the
weight along the shaft until it exactly counterbalances the
telescope (Figure 4a). That’s the point at which the shaft
remains horizontal even when you let go with both hands
(Figure 4b).

3. Retighten the counterweight lock knob. The telescope is
now balanced on the right ascension axis.

The telescope should be balanced in the Dec. axis already if
you have properly centered the 1/4"-20 mounting block on the
optical tube relative to the tube rings.

Now when you loosen the lock lever on one or both axes and
manually point the telescope, it should move without resist­ance and should not drift from where you point it.

5. Using Your Telescope

Focusing the Telescope

With the 25mm eyepiece inserted in the diagonal, move the
telescope so the front (open) end is pointing in the general
direction of an object at least 1/4-mile away. Now, with your
fingers, slowly rotate one of the focusing knobs until the object
comes into sharp focus.Go a little bit beyond sharp focus until
the image just starts to blur again, then reverse the rotation of
the knob, just to make sure you’ve hit the exact focus point.

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Figure 4a, 4b. Proper operation of the equatorial mount requires that the telescope tube be balanced on the R.A. axis. (a) With the R.A.

lock lever released, slide the counterweights along the counterweight shaft until it just counterbalances the tube. (b) When you let go with
both hands, the tube should not drift up or down.The telescope tube should already be balanced in the Dec. axis if you have properly
centered the 1/4" mounting block between the tube rings.

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NOTE:The image in the telescope will appear reversed
left-to-right).This is normal for astronomical telescopes
that utilize a star diagonal.The finder scope view will be
rotated 180° (see Figure 5).

If you have trouble focusing, rotate the focusing knob so the
drawtube is in as far as it will go. Now look through the eye­piece while slowly rotating the focusing knob in the opposite
direction. You should soon see the point at which focus is
reached.

The metal thumb screw on the top of the body of the focuser
will lock the focuser drawtube in place once the telescope is
properly focused. Before focusing, remember to first loosen
this thumb screw.

Viewing with Eyeglasses

If you wear eyeglasses, you may able to keep them on while
you observe, if the eyepiece has enough “eye relief” to allow
you to see the whole field of view.You can try this by looking
through the eyepiece first with your glasses on, and then with
them off, and see if the glasses restrict the view to only a por­tion of the full field.If they do, y ou can easily observe with your
glasses off by just re-focusing the telescope the needed
amount. If you suffer from severe astigmatism, however, you
may find images noticeably sharper with your glasses on.

Aligning the Finder Scope

The SkyView Pro 100 EQ comes with a 6x30 achromatic find­er scope (Figure 3a).The number 6 means six-times magnifi­cation and the 30 indicates a 30mm diameter front lens.The
finder scope makes it easier to locate the subject you want to
observe in the telescope, because the finder scope has a
much wider field-of-view.

The finder scope uses a spring-loaded bracket that makes
alignment of the finderscope very easy. As you turn either of

the thumbscrews, the spring in the bracket’s tensioner moves
in and out to keep the finder scope secure in the bracket.

The finder scope must be aligned accurately with the tele­scope for proper use.To align it, first aim the main telescope
at an object at least a 1/4 mile away—the top of a telephone
pole, a chimney, etc. First loosen the R.A. and Dec. lock levers
and move the telescope until it is pointing towards the desired
object; sight along the tube to aim the telescope. Turn the
focus knob until the object is properly focused.Make sure to
position the object in the center of the telescope’s ey epiece b y
turning the R.A. and declination slow-motion control knobs
(the R.A. and Dec. lock levers must be tightened to use the
slow-motion control knobs).

Now look in the finder scope.Is the object visible? Ideally it will
be somewhere in the field of view. If not, some coarse adjust­ment to the finder scope bracket’s alignment thumbscrews will
be needed until the object comes into the finder scope’s field
of view.

With the image in the finder scope’s field of view, you now
need to fine-adjust the alignment thumbscrews to center the
object on the intersection of the crosshairs. Adjust the aim of
the finder scope by turning the thumbscrews, one at a time,
until the object is centered. Make sure the object is still cen­tered in the telescope’s eyepiece as well. If it is not still cen­tered in the eyepiece you will need to repeat the process.

The finder scope alignment needs to be checked before every
observing session. This can easily be done at night, before
viewing through the telescope.Choose any bright star or plan­et, center the object in telescope eyepiece, and then adjust
the finder scope bracket’s alignment thumbscrews until the
star or planet is centered on the finder’s crosshairs.

Focusing the finder scope

If, when you look through the finder scope, the images appear
somewhat out of focus, you will need to refocus the finder
scope for your eyes. Loosen the lock ring located behind the
objective lens cell on the body of the finder scope (see Figure
3a). Back the lock ring off by a few turns, for now.Refocus the
finder scope on a distant object by threading the objective
lens cell in or out of the finderscope body .Precise focusing will
be achieved by focusing the finder scope on a bright star.
Once the image appears sharp, retighten the locking ring
behind the objective lens cell.The finder scope’s focus should
not need to be adjusted again.

Magnification & Eyepieces

Magnification, or power, is determined by the focal length of
the telescope and the focal length of the eyepiece.Therefore,
by using eyepieces of different focal lengths, the resultant
magnification can be varied.

Magnification is calculated as follows:

Telescope Focal Length (mm)

Magnification =

Eyepiece Focal Length (mm)

View through the SkyView Pro 100 EQ

Figure 5. Images through the finder scope will appear

upside-down and backwards (rotated 180°).Images through the
SkyView Pro 100 EQ with its diagonal in place will be reversed from
left-to right.

View through finder scope

The SkyView Pro 100 EQ has a focal length of 600mm, which
when used with the supplied 25mm eyepiece yields:

600mm÷25mm= 24x

The magnification provided by the 10mm eyepiece is:

600mm÷10mm=60x

The maximum attainable magnification for a telescope is
directly related to how much light it can gather.The larger the
aperture, the more magnification is possible. In general a fig­ure of 2x per millimeter of aperture is the maximum attainable
for most telescopes.Your SkyView Pro 100 EQ has an aper­ture of 100 millimeters, so the maximum magnification would
be about 200x.This level of magnification assumes you have
ideal conditions for viewing.

Keep in mind that as you increase magnification, the bright­ness of the object viewed will decrease; this is an inherent
principle of the laws of physics and cannot be av oided.If mag­nification is doubled, an image appears four times dimmer. If
magnification is tripled, image brightness is reduced by a fac­tor of nine!

Always start with your lowest power eyepiece and work your
way up. Start by centering the object being viewed in the
25mm eyepiece. Then increase the magnification to get a
closer view , if you wish.If the object is off-center (i.e., it is near
the edge of the field of view) you will lose it when you increase
magnification, since the field of view will be narrower with the
higher-powered eyepiece. To change eyepieces, first loosen
the securing thumbscrews on the diagonal.Then carefully lift
the eyepiece out of the diagonal. Do not tug or pull the eye­piece to the sides, as this will knock the telescope off its tar­get.Replace the eyepiece with the new one b y sliding it gently
into the diagonal.Re-tighten the thumbscrews, and refocus f or
your new magnification.

Use of 2" Eyepieces

A feature of the SkyView Pro 100 EQ is its ability to use either

1.25" or 2" barrel-diameter eyepieces.At low magnifications,
2" eyepieces can give a wider field of vie w than standard 1.25"
eyepieces.This is especially desirable for observing deep-sky
objects, as many of them appear quite large, but faint. If you
want to use 2" eyepieces, you will also need to use a 2" star
diagonal for refractors, or a 2" e xtension tube , so that the tele­scope will properly come to focus.

To use 2" eyepieces, simply loosen the two large thumb­screws on the 2" adapter that are just in front of the thumb­screw that holds the provided 1.25" star diagonal in place.
Once these thumbscrews are loosened, the entire back end of
the focuser, including any 1.25" diagonal and eyepiece that
may be attached, comes off, e xposing the 2" diameter focuser
drawtube Now, insert your 2" star diagonal into the drawtube
and secure with the two thumbscrews loosened previously.
Insert a 2" eyepiece into the diagonal, secure it in place with
the thumbscrew on the diagonal, and you’re ready to observe.

Note About Chromatic Aberration

Chromatic aberration literally means color distortion. When­ever light passes through one material to another, light of dif-

ferent wavelengths (color) is bent by different amounts.This is
a problem that plagues refractor-type telescopes, since light
passes through both air and glass to form an image. Most
astronomical objects emit a spectrum comprised of many dif­ferent wav elengths of light, so each wa v elength will be bent b y
a slightly different amount when passing through a lens.This
results in each color of light reaching precise focus at a slight­ly different point, which will provide unacceptable images.

Achromatic refractors, like the SkyView Pro 100 EQ, are
designed to minimize chromatic aberration to acceptable lev­els.The objective lens is actually comprised of two individual
lenses, called elements, made of different materials, which
bend light in slightly different ways. By precisely spacing and
shaping the elements, the chromatic aberration incurred when
light passes through air and the first glass element is reduced
by the way the second element bends the light.The result is
an image that is much better color corrected than a non­achromatic (one element) objective lens.

Even with the achromatic lens design, however, the SkyView
Pro 100 EQ will suffer a bit from chromatic aberration due to
its relatively large aperture and short focal length.This will be
noticeable, to some degree, on extremely bright objects, such
as the Moon and bright planets.What you will notice is that the
object, when focused, has a slight “purple-halo”around it.This
will not present a problem for most observers, as the eye
readily adapts to the view and is still able to distinguish fine
details. Chromatic aberration will never inhibit deep sky
observing, as deep sky objects are too faint to cause any
noticeable color distortion.

6. Setting Up and Using the
Equatorial Mount

When you look at the night sky, you no doubt have noticed
that the stars appear to move slowly from east to west over
time.That apparent motion is caused by the Earth’s rotation
(from west to east). An equatorial mount (Figure 6) is
designed to compensate for that motion, allowing you to easi­ly “tr ack”the movement of astronomical objects, thereby k eep­ing them from drifting out of your telescope’s field of view
while you’re observing.

This is accomplished by slowly rotating the telescope on its
right ascension (R.A.) axis, using only the R.A. slow-motion
knob.But first the R.A.axis of the mount must be aligned with
the Earth’s rotational (polar) axis—a process called polar
alignment.

Polar Alignment

For Northern Hemisphere observers, approximate polar align­ment is achieved by pointing the mount’s right ascension axis
at the North Star, or Polaris.It lies within 1° of the north celes­tial pole (NCP), which is an extension of the Earth’s rotational
axis out into space.Stars in the Norther n Hemisphere appear
to revolve around the NCP.

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To find Polaris in the sky, look nor th and locate the patter n of
the Big Dipper (Figure 7). The two stars at the end of the
“bowl” of the Big Dipper point right to Polaris.

Observers in the Southern Hemisphere aren’t so fortunate to
have a bright star so near the south celestial pole (SCP).The
star Sigma Octantis lies about 1° from the SCP, but it is barely
visible with the naked eye (magnitude 5.5).

For general visual observation, an approximate polar align­ment is sufficient.

1. Level the equatorial mount by adjusting the length of the
three tripod legs.

2. There are two latitude adjustment L-bolts (see Figure 6);
loosen one while tightening the other.By doing this you will
adjust the latitude of the mount. Continue adjusting the
mount until the pointer on the latitude 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.The latitude set-

ting should not have to be adjusted again unless you mo v e
to a different viewing location some distance away.

3. Loosen the Dec. lock lever and rotate the telescope’s opti­cal tube until it is parallel with the right ascension axis, as
it is in Figure 6.

4. Move the tripod so the telescope tube and right ascension
axis point roughly at Polaris. If you cannot see Polaris
directly from your observing site, consult a compass and
rotate the tripod so the telescope points north. There is a
label bearing a large “N” at the base of the equatorial
mount (Figure 8). It should be facing north.

The equatorial mount is now polar aligned for casual observ­ing. More precise polar alignment is recommended for
astrophotography. For this we suggest using the optional polar
axis finder scope

From this point on in your observing session, you should not
make any further adjustments to the latitude of the mount, nor
should you move the tripod.Doing so will undo the polar align-

Figure 6. The SkyView Pro mount.

R.A. setting circle
Polar axis finder

scope (optional)
Latitude scale

(opposite side)
Latitude

adjustment
L-bolts

Dec. slow-motion
control knob

Dec. setting circle
Dec. lock lever
Front opening
R.A. lock lever
R.A. slow-motion

control knob

D

e

c

lin

a

t

io

n

A

x

is

Right

Ascension

Axis

Figure 8. For polar alignment, position the tripod so that the "N"

label at the base of the mount faces north.The azimuth fine
adjustment knobs above it are used to make small adjustments to the
mount’s azimuth position.Be cer tain to loosen the tr ipod attachment
knob on the central support shaft before adjusting these knobs.

Azimuth
adjustment
knobs

Figure 7. To find Polaris in the night sky, look north and find the

Big Dipper.Extend an imaginar y 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)

Cassiopeia

N.C.P.

P

oin

ter

S

tars

Polaris

9

ment.The telescope should be moved only about its R.A. and
Dec. axes.

Polar Alignment Using an Optional Polar Axis
Finder Scope

The SkyView Pro 100 EQ mount can be equipped with an
optional polar axis finder scope (Figure 9a) which goes inside
the right ascension axis of the mount. When properly aligned
and used, it makes accurate polar alignment quick and easy
to do.

To install the polar axis finder scope, remove the cover at the
rear of the mount’s right ascension axis (Figure 9b) and
thread the polar axis finder scope into the equatorial mount
until tight.

Alignment of the Polar Axis Finder Scope

1. Look through the polar finder at a distant object (during the
day) and center it in the crosshairs.Y ou ma y need to adjust
the latitude adjustment L-bolts and the tripod position to do
this.

2. Rotate the mount 180º about the R.A. axis. Again, it may
be convenient to remove the counterweights and optical
tube first.

3. Look through the polar finder again. Is the object being
viewed still centered on the crosshairs? If it is, then no fur­ther adjustment is necessary.If not, then look through the
polar finder while rotating the mount about the R.A. axis.
You will notice that the object you have previously cen­tered moves in a circular path. Use the three alignment
setscrews on the polar axis finder to redirect the cross­hairs of the polar finder to the apparent center of this cir­cular path. Repeat this procedure until the position that
the crosshairs point to does not rotate off-center when the
mount is rotated in R.A. Once this is accomplished,
retighten the thumbscrews.

The polar axis finder scope is now ready to be used.When not in
use, replace the plastic protective cov er to pre v ent the polar find­er from getting bumped, which could knock it out of alignment.

Using the Polar Axis Finder Scope

The reticle of the polar axis finder scope for the SkyView Pro
has a tiny star map printed on it that makes precise polar

alignment quick and easy. If you do not have a clear view of
Polaris from your observing site, you will not be able to use
the polar-axis finder to precisely polar align the telescope.To
align the mount using the polar axis finder scope, follow these
instructions:

1. Approximately polar-align the mount as outlined in the pro­cedure above.

2. Loosen the Dec. lock lever and rotate the optical tube on
the declination axis so that the tube is at a 90° to the right
ascension axis (Figure 10). Tighten the Dec. lock lever.
This will allow you to view through the mount with the polar
axis finder scope.

3. Remove the cap on the front of the equatorial mount
(Figure 6). Focus the polar finder by rotating the eyepiece.
Now, sight Polaris in the polar axis finder scope. If you
have followed the approximate polar alignment procedure
accurately, Polaris will probably be within the field of view.
If not, move the tripod left-to-right, and adjust the latitude

Figure 9b. Installing the optional polar axis finder scope.

Figure 10. The optical tube must be at a 90° angle to the right

ascension axis in order to view through the polar axis finder.

Figure 9a. The optional polar axis finder scope.

Eyepiece
focus ring

Alignment
set screws (3)

Focus
lock ring

Objective
lens

up-and down until Polaris is somewhere within the field of
view of the polar axis finder scope.

4. Shine a red flashlight down the front end of the polar find­er to illuminate the reticle within the field of view. Make
sure the flashlight shines in at an angle, so as not to block
the polar finder’s field of view. It may be helpful to have a
friend hold the flashlight while you look through the polar
finder. Note the constellation Cassiopeia and the Big
Dipper in the reticle.They do not appear in scale, but they
indicate the general positions of Cassiopeia and the Big
Dipper relative to the north celestial pole (which is indicat­ed by the cross at the center of the reticle).Rotate the reti­cle so the constellations depicted match their current ori­entation in they sky when viewed with the naked e y e.To do
this, release the R.A. lock lever and rotate the main tele­scope around the R.A. axis until the reticle is oriented with
sky. For larger optical tubes, you may need to remove the
tube from the mount to prevent it from bumping into the
mount. Once the reticle is correctly oriented, use the r ight
ascension lock lever to secure the mount’s position.

5. Now use the azimuth adjustment knobs (Figure 8) and the
latitude adjustment L-bolts (Figure 6) on the mount to posi­tion the star Polaris inside the tiny circle marked “Polaris”
on the finder’s reticle.You must first loosen the knob under­neath the equatorial mount on the center support shaft to
use the azimuth adjustment knobs.Once Polaris is proper­ly positioned within the reticle, you are precisely polar
aligned. Retighten the knob underneath the equatorial
mount.

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 telescope should be moved only about its
right ascension and declination axes.

Additional Note Regarding Focusing the Polar
Axis Finder Scope

The polar axis finder scope is normally focused by simply
rotating the eyepiece focus ring.However , if after adjusting the
focus ring you find that the image of the reticle is sharp, but
the stars are out of focus, then you must adjust the focus of
the polar axis finder’s objective lens. To do this, first remove
the polar axis finder from the mount. Look through the polar
axis finder at a star (at night) or distant object at least 1/4 mile
away (during daylight). Use the eyepiece focus ring to bring
the reticle into sharp focus. Now, loosen the focus lock ring
(Figure 9a) and thread the entire objective end of the finder
inwards or outwards until images appear sharp.Re-tighten the
focus lock ring. Once the polar axis finder’s objective lens is
focused, it should not need to be adjusted again.

Use of the Right Ascension and Declination
Slow-Motion Control Knobs

The right ascension (R.A.) and declination (Dec.) slow-motion
control knobs allow fine adjustment of the telescope’s position
to center objects within the field of view. Before you can use

the knobs, you must manually “slew” the mount to point the
telescope in the vicinity of the desired target. Do this by loos­ening the R.A. and Dec. lock levers and moving the telescope
about the mount’s right ascension and declination axes. Once
the telescope is pointed close to the object to be viewed,
retighten both lock levers.

The object should now be visible somewhere in the tele­scope’s finder scope.If it isn’t, use the slow-motion knobs to
scan the surrounding area of sky.When the object is visible in
the finder scope, use the slow-motion knobs to center it.Now,
look in the telescope’s 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 eyepiece, use the
slow-motion knobs to center it in the field of view.

Note: If you have an optional motor drive attached,
you will need to loosen the manual clutch on the R.A.
(and Dec. for dual-axis drives) worm gear shaft before
using the slow-motion control knob.

Tracking Celestial Objects

When you observe a celestial object through the telescope,
you’ll see it drift slowly across the field of view.To keep it in the
field, if your equatorial mount is polar aligned, just turn the
R.A. slow-motion control knob clockwise. The Dec. slow­motion control knob is not needed for tracking. Objects will
appear to move faster at higher magnifications, because the
field of view is narrower.

Optional Motor Drives for Automatic Tracking

An optional DC motor drive can be mounted on the R.A. axis
of the equatorial mount to provide hands-free tracking.
Objects will then remain stationary in the field of view without
any manual adjustment of the right ascension slow-motion
control knob.

Understanding the Setting Circles

The setting circles on an equatorial mount enable you to
locate celestial objects by their “celestial coordinates”.Every
object resides in a specific location on the “celestial sphere”.
That location is denoted by two numbers: its right ascension
(R.A.) and declination (Dec.). In the same way, every location
on Earth can be described by its longitude and latitude. Right
ascension is similar to longitude on Earth, and declination is
similar to latitude. The R.A. and Dec. values for celestial
objects can be found in any star atlas or star catalog.

The R.A. setting circle is scaled in hours, from 1 through 24,
with small marks in between representing 10-minute incre­ments (there are 60 minutes in 1 hour of right ascension).The
lower set of numbers apply to viewing in the Northern
Hemisphere, while the numbers above them apply to viewing
in the Southern Hemisphere.

The Dec. setting circle is scaled in degrees, with each mark
representing 2° increments.Values of declination coordinates
range from +90° to -90°. The 0° mark indicates the celestial
equator.When the telescope is pointed nor th of the celestial
equator, values of the declination setting circle are positive;

10

when the telescope is pointed south of the celestial equator,
values of the declination setting circle are negative.

So, the coordinates for the Orion Nebula listed in a star atlas
will look like this:

R.A. 5h 35.4m Dec. –5° 27'

That’s 5 hours and 35.4 minutes in right ascension, and -5
degrees and 27 arc-minutes in declination (there are 60 arc­minutes in 1 degree of declination).

Before you can use the setting circles to locate objects, the
mount must be accurately polar aligned, and the setting cir­cles must be calibrated.

Calibrating the Declination Setting Circle

1. Loosen the Dec. lock lever and position the telescope as
accurately as possible in declination so it is parallel to the
R.A. axis as shown in Figure 1. Re-tighten the lock lever.

2. Loosen one of the thumbscrews on the Dec. setting circle,
this will allow the setting circle to rotate freely. Rotate the
Dec. setting circle until the pointer reads exactly 90°.Re-
tighten the setting circle thumbscrew.

Calibrating the Right Ascension Setting Circle

1. Identify a bright star in the sky near the celestial equator
(declination = 0°) and look up its coordinates in a star
atlas.

2. Loosen the R.A. and Dec. lock levers on the equatorial
mount, so the telescope optical tube can move freely.

3. Point the telescope at the bright star whose coordinates
you know. Lock the R.A. and Dec. lock levers. Center the
star in the telescope’s field of view with the slow-motion
control knobs.

4. Loosen one of the R.A. setting circle thumbscrews (see
Figure 11); this will allow the setting circle to rotate freely.
Rotate the setting circle until the R.A. pointer arrow indi­cates the R.A. coordinate listed in the star atlas for the
object. Re-tighten the setting circle thumbscrew.

Finding Objects With the Setting Circles

Now that both setting circles are calibrated, look up in a star
atlas the coordinates of an object you wish to view.

1. Loosen the Dec. lock lever and rotate the telescope until
the declination value from the star atlas matches the read­ing on the Dec.setting circle.Remember that values of the
Dec.setting circle are positive when the telescope is point­ing north of the celestial equator (Dec. = 0°), and negative
when the telescope is pointing south of the celestial equa­tor.Retighten the lock lever.

2. Loosen the R.A. lock lever and rotate the telescope until
the right ascension value from the star atlas matches the
reading on the R.A. setting circle. Remember to use the
lower set of numbers on the R.A. setting circle. Retighten
the lock lever.

Most setting circles are not accurate enough to put an object
dead-center in the telescope’s eyepiece, but they should
place the object somewhere within the field of view of the find­er scope, assuming the equatorial mount is accurately polar
aligned. Use the slow-motion controls to center the object in
the finder scope, and it should appear in the telescope’s field
of view.

The setting circles must be re-calibrated every time you wish
to locate a new object. Do so by calibrating the setting circles
for the centered object before mo ving on to the next one.

Confused About Pointing the Telescope?

Beginners occasionally experience some confusion about
how to point the telescope overhead or in other directions.In
Figure 1 the telescope is pointed north as it would be during
polar alignment. The counterweight shaft is oriented down­ward. But it will not look like that when the telescope is point­ed in other directions.Let’s say you want to view an object that
is directly overhead, at the zenith.How do you do it?

DO NOT make any adjustment to the latitude adjustment
L-bolts.That will spoil the mount’s polar alignment.Remember,
once the mount is polar aligned, the telescope should be
moved only on the R.A.and Dec.axes.To point the scope over­head, first loosen the R.A. lock lever and rotate the telescope
on the right ascension axis until the counterweight shaft is hor­izontal (parallel to the ground).Then loosen the Dec. lock lever
and rotate the telescope until it is pointing straight overhead.
The counterweight shaft is still horizontal.Then retighten both
lock levers.

What if you need to aim the telescope directly north, but at an
object that is nearer to the horizon than Polaris? You can’t do
it with the counterweight down as pictured in Figure 1. Again,
you have to rotate the scope in right ascension so that the
counterweight shaft is positioned horizontally.Then rotate the
scope in declination so it points to where you want it near the
horizon.

To point the telescope directly south, the counterweight shaft
should again be horizontal.Then you simply rotate the scope
on the declination axis until it points in the south direction.

Figure 11. The R.A. and Dec. setting circles.

11

Dec.
setting circle

Dec.
setting circle
thumbscrew
(2)

Dec.
indicator
arrow

R.A.
indicator
arrow

R.A. setting circle

thumbscrew (2)

R.A.
setting circle

12

To point the telescope to the east or west, or in other direc­tions, you rotate the telescope on its right ascension and dec­lination axes.Depending on the altitude of the object you want
to observe, the counterweight shaft will be oriented some­where between vertical and horizontal.

Figure 12 illustrates how the telescope will look when pointed
at the four cardinal directions:north, south, east and west.

7. Astronomical Observing

For many users, the SkyView Pro 100 EQ telescope will be a
major leap into the world of amateur astronomy.This section
is intended to get you ready for your v o yages through the night
sky.

Observing Tips

A. Site Selection

Pick a location awa y from street lights and bright yard lighting.
Avoid viewing over rooftops and chimneys, as the y often have
warm air currents rising from them, which distort the image
seen in the eyepiece. Similarly, you should not observe
through an open or closed window from indoors. Better yet,
choose a site out-of-town, away from any “light pollution”.
You’ll be stunned at how many more stars you’ll see! Most
importantly, make sure that any chosen site has a clear view
of a large portion of the sky.

B. Seeing and Transparency

Atmospheric conditions play a huge part in quality of viewing.
In conditions of good “seeing”, star twinkling is minimal and
objects appear steady in the eyepiece. Seeing is best over-

head, worst at the horizon. Also, seeing generally gets better
after midnight, when much of the heat absorbed by the Earth
during the day has radiated off into space.Typically, seeing
conditions will be better at sites that have an altitude over
about 3000 feet. Altitude helps because it decreases the
amount of distortion causing atmosphere you are looking
through.

A good way to judge if the seeing is good or not is to look at
bright stars about 40° above the horizon.If the stars appear to
“twinkle”, the atmosphere is significantly distorting the incom­ing light, and views at high magnifications will not appear
sharp. If the stars appear steady and do not twinkle, seeing
conditions are probably good and higher magnifications will
be possible.Also, seeing conditions are typically poor during
the day. This is because the heat from the Sun war ms the air
and causes turbulence.

Good “transparency” is especially important for observing
faint objects. It simply means the air is free of moisture,
smoke, and dust. All tend to scatter light, which reduces an
object’s brightness.

One good way to tell if conditions are good is by how many
stars you can see with your naked e ye .If you cannot see stars
of magnitude 3.5 or dimmer then conditions are poor.
Magnitude is a measure of how bright a star is, the brighter a
star is, the lower its magnitude will be.A good star to remem­ber for this is Megrez (mag.3.4), which is the star in the “Big
Dipper” connecting the handle to the “dipper”. If you cannot
see Megrez, then you have fog, haze, clouds, smog, light pol­lution or other conditions that are hindering your viewing (See
Figure 13).

C. Cooling the Telescope

All optical instruments need time to reach “thermal equilibri­um” to achieve maximum stability of the lenses, which is
essential for peak performance. When moved from a warm
indoor location outside to cooler air (or vice-versa), a tele­scope needs time to cool to the outdoor temperature.The big­ger the instrument and the larger the temperature change, the
more time will be needed.

Allow at least 30 minutes for your SkyView Pro 100 EQ to
equilibrate. If the scope has more than a 40° temperature
adjustment, allow an hour or more. In the winter, storing the

Figure 13. Megrez connects the Big Dipper’s handle to it's “pan”.

It is a good guide to how conditions are. If you can not see Megrez
(a 3.4 mag star) then conditions are poor.

Figure 12a-d. This illustration shows the telescope pointed in

the four cardinal directions (a) north, (b) south, (c) east, (d) west.
Note that the tripod and mount have been moved;only the telescope
tube has been moved on the R.A.and Dec. axes.

ab

cd

1.9

4.9

2.4

1.9

2.4

1.7

3.4

2.5

telescope outdoors in a shed or garage greatly reduces the
amount of time needed for the optics to stabilize.It also is a
good idea to keep the scope covered until the Sun sets so the
tube does not heat greatly above the temperature of the out­side air.

D. Let Your Eyes Dark-Adapt

Do not expect to go from a lighted house into the darkness of
the outdoors at night and immediately see faint nebulas,
galaxies, and star clusters- or even very many stars, for that
matter. Your eyes take about 30 minutes to reach perhaps
80% of their full dark-adapted sensitivity. Many observers
notice improvements after several hours of total darkness. As
your eyes become dark-adapted, more stars will glimmer into
view and you will be able to see fainter details in objects you
view in your telescope.So give yourself at least a little while to
get used to the dark before you begin observing. Also, expos­ing your eyes to very bright daylight for extended periods of
time can adversely affect your night vision for days.

To see what you are doing in the darkness, use a red-filtered
flashlight rather than a white light. Red light does not spoil
your eyes’ dark adaptation like white light does. A flashlight
with a red LED light is ideal, or you can cover the front of a
regular incandescent flashlight with red cellophane or paper.
Beware, too, that nearby porch and streetlights and automo­bile headlights will spoil your night vision.

Eyepiece Selection

By using eyepieces of varying focal lengths, it is possible to
attain many magnifications with the SkyView Pro 100 EQ.The
telescope comes with two high-quality Sirius Plÿssl eye­pieces: a 25mm, which gives a magnification of 24x, and a
10mm, which gives a magnification of 60x. Other eyepieces
can be used to achieve higher or low er powers .It is quite com­mon for an observer to own five or more eyepieces to access
a wide range of magnifications. This allows the observer to
choose the best eyepiece to use depending on the object
being viewed. At least to begin with, the two supplied eye­pieces will suffice nicely.

Whatever you choose to view, always start by inserting your
lowest power (longest focal length) eyepiece to locate and
center the object. Low magnification yields a wide field of
view, which shows a larger area of sky in the eyepiece.This
makes acquiring and centering an object much easier.If you
try to find and center objects with high power (narrow field of
view), it’s like trying to find a needle in a haystack!

Once you’ve centered the object in the eyepiece, you can
switch to higher magnification (shorter focal length eyepiece),
if you wish. This is especially recommended for small and
bright objects, like planets and double stars.The Moon also
takes higher magnifications well.

Deep-sky objects, however, typically look better at medium or
low magnifications.This is because many of them are quite
faint, yet have some extent (apparent width). Deep-sky
objects will often disappear at higher magnifications, since
greater magnification inherently yields dimmer images.This is
not the case for all deep-sky objects, however. Many galaxies

are quite small, yet are somewhat bright, so higher power ma y
show more detail.

The best rule of thumb with eyepiece selection is to start with
a low power, wide field, and then work your way up in magnifi­cation. If the object looks better, try an even higher magnifica­tion. If the object looks worse, then back off the magnification
a little by using a lower power eyepiece.

What to Expect

So what will you see with your telescope? You should be able
to see bands on Jupiter, the rings of Saturn, craters on the
moon, the waxing and waning of Venus, and possibly hun­dreds of deep sky objects.Do not expect to see as much color
as you in NASA photos, since those are taken with long-e xpo­sure cameras and have “false color” added. Our eyes are not
sensitive enough to see color in deep-sky objects except in a
few of the brightest ones.

Remember that you are seeing these objects using your own
telescope with your own eyes! The object you see in your e y e­piece is in real-time, and not some conveniently provided
image from an expensive space probe. Each session with
your telescope will be a learning experience. Each time you
work with your telescope it will get easier to use, and stellar
objects will become easier to find.Take it from us, there is big
difference between looking at a well-made full-color NASA
image of a deep-sky object in a lit room during the daytime,
and seeing that same object in your telescope at night. One
can merely be a pretty image someone gave to you.The other
is an experience you will never forget!

A.The Moon

With is rocky and cratered surface, the moon is one of the
most interesting and easy subjects for your scope.The best
time to view it is during its partial phases when shadows fall
on the craters and canyon walls to give its features definition.
While the full moon may look like a tempting target, it is actu­ally the worst time for viewing! The light of a full moon is too
bright and lacks any decent surface definition.

Use an optional Moon filter to dim the Moon when it is very
bright. It simply threads onto the bottom of the eyepiece from
the focuser (you must first remove the eyepiece from the
focuser to attach the filter).You’ll find the Moon filter improves
viewing comfort, and helps bring out the subtle features if the
lunar surface.

B.The Sun

You can change your nighttime telescope into a daytime Sun
viewer by installing an optional full-aperture solar filter over
the front opening of a SkyView Pro 100 EQ. The primary
attraction is sunspots, which change shape, appearance, and
location daily.Sunspots are directly related to magnetic activi­ty in the Sun. Many observers like to make drawings of
sunspots to monitor how the Sun is changing from day to day.

Important Note: Do not look at the Sun with any opti­cal instrument without a professionally made solar fil­ter, or permanent eye damage could result. Also, be
sure to cover the finder scope, or better yet, remove it
altogether.

13

14

C.The Planets

The planets don’t stay put like the stars, so to find them you
should refer to Sky Calendar at our website telescope.com, or
to charts published monthly in Astronomy, Sky & Telescope,
or other astronomy magazines. Venus, Mars, Jupiter, and
Saturn are the brightest objects in the sky after the Sun and
the Moon.Your SkyView Pro 100 EQ is capable of showing
you these planets in some detail.Other planets may be visible
but will likely appear starlike.Because planets are quite small
in apparent size, optional higher power eyepieces are recom­mended and often needed for detailed observations. Not all
the planets are generally visible at any one time.

JUPITER The largest planet, Jupiter, is a great subject for
observation. You can see the disk of the giant planet and
watch the ever-changing positions of its four largest moons—
Io, Callisto, Europa, and Ganymede. Higher power eyepieces
should bring out the cloud bands on the planet’s disk.

SATURN The ringed planet is a breathtaking sight when it is
well positioned.The tilt angle of the r ings varies over a period
of many years; sometimes they are seen edge-on, while at
other times they are broadside and look like giant “ears” on
each side of Saturn’s disk. A steady atmosphere (good see­ing) is necessary for a good view. You will probably see a
bright “star” close by, which is Saturn’s brightest moon, Titan.

VENUS At its brightest, Venus is the most luminous object in
the sky, excluding the Sun and the Moon. It is so bright that
sometimes it is visible to the naked eye during full daylight!
Ironically, Venus appears as a thin crescent, not a full disk,
when at its peak brightness.Because it is so close to the Sun,
it never wanders too far from the morning or evening horizon.
No surface markings can be seen on Venus, which is always
shrouded in dense clouds.

MARS The Red Planet makes its closest approach to Earth
every two years. During close approaches you’ll see a red
disk, and may be able to see the polar ice cap.To see surface
detail on Mars, you will need a high power eyepiece and very
steady air!

D.The Stars

Stars will appear like twinkling points of light. Even powerful
telescopes cannot magnify stars to appear as more than a
point of light! You can, however, enjoy the different colors of
the stars and locate many pretty double and multiple stars.
The famous “Double-Double” in the constellation Lyra and the
gorgeous two-color double star Albireo in Cygnus are
fav orites.Defocusing a star slightly can help bring out its color.

E. Deep-Sky Objects

Under dark skies, you can observe a wealth of fascinating
deep-sky objects, including gaseous nebulas, open and globu­lar star clusters, and a variety of different types of galaxies.
Most deep-sky objects are very faint, so it is important that you
find an observing site well away from light pollution.Take plen­ty of time to let your eyes adjust to the darkness.Do not expect
these subjects to appear like the photographs you see in
books and magazines; most will look like dim gray smudges.
But as you become more experienced and your observing

skills get sharper, you will be able to ferret out more and more
subtle details and structure.

How to Find Deep-sky Objects: Starhopping

Starhopping, as it is called by astronomers, is perhaps the
simplest way to hunt down objects to view in the night sky. It
entails first pointing the telescope at a star close to the object
you wish to observe, and then progressing to other stars clos­er and closer to the object until it is in the field of view of the
eyepiece. It is a very intuitive technique that has been
employed for hundreds of years by professional and amateur
astronomers alike. Keep in mind, as with any new task, that
starhopping may seem challenging at first, but will become
easier over time and with practice.

To starhop, only a minimal amount of additional equipment is
necessary. A star chart or atlas that shows stars to at least
magnitude 5 is required. Select one that shows the positions
of many deep-sky objects, so you will have a lot of options to
choose from.If you do not know the positions of the constella­tions in the night sky, you will need to get a planisphere to
identify them.

Start by choosing bright objects to view.The brightness of an
object is measured by its visual magnitude; the brighter an
object, the lower its magnitude.Choose an object with a visu­al magnitude of 9 or lower. Many beginners start with the
Messier objects, which represent some of the best and bright­est deep-sky objects, first catalogued about 200 years ago by
the French astronomer Charles Messier.

Determine in which constellation the object lies. Now, find the
constellation in the sky. If you do not recognize the constella­tions on sight, consult a planisphere.The planisphere gives an
all-sky view and shows which constellations are visible on a
given night at a given time.

Now, look at your star chart and find the brightest star in the
constellation that is near the object you are trying to find.
Using the finder scope, point the telescope at this star and
center it on the crosshairs. Next, look again at the star chart
and find another suitably bright star near the bright star cur­rently centered in the finder.Keep in mind that the field of view
of the finder scope is approximately 7°, so you should choose
another star that is no more that 7° from the first star, if possi­ble.Move the telescope slightly , until the telescope is centered
on the new star.

Continue using stars as guideposts in this way until you are at
the approximate position of the object you are trying to find
(Figure 14). Look in the telescope’s eyepiece, and the object
should be somewhere within the field of view.If it’s not, sw eep
the telescope carefully around the immediate vicinity until the
object is found.

If you have trouble finding the object, start the starhop again
from the brightest star near the object you wish to view.This
time, be sure the stars indicated on the star chart are in fact
the stars you are centering in the eyepiece. Remember, the
finder scope (and main telescope eyepiece, for that matter)
gives an inverted image, so you must keep this in mind when
starhopping from star to star.

15

8. Terrestrial Observing

The SkyView Pro 100 optical tube can be used for long-dis­tance viewing over land.For this we recommend using a 45°
correct-image diagonal instead of the provided 90° mirror star
diagonal. The correct-image diagonal will yield upright, non­reversed images and provides a more comfortable viewing
angle.An optional altazimuth mount or a sturdy camera tripod,
as opposed to the SkyView Pro equatorial mount, is also rec­ommended for terrestrial viewing.This is because the equato­rial mount is designed for tracking the motion of stars, and is
not as easy to aim at terrestrial objects.The SkyView Pro 100
EQ’s optical tube has a mounting block that will accept a
1/4"-20 thread used on most camera tripods.

For terrestrial viewing, it’s best to stick with low power eye­pieces that yield a magnification of under 100x.At higher pow­ers, images rapidly lose sharpness and clarity due to “heat
waves” caused by Sun-heated air.

Remember to aim well clear of the Sun, unless the front of the
telescope is fitted with a professionally made solar filter and
the finder scope is covered by an opaque material or remov ed
altogether.

9. Astrophotography

Several different types of astrophotography can be success­fully attempted with the SkyView Pro 100 EQ.

Moon Photography

This is perhaps the simplest form of astrophotography, as no
motor drive is required. All that is needed is a T-ring for your
specific camera model. Attach the T-ring to your camera body
and thread the T-ring directly onto the focuser drawtube.Point
the telescope toward the Moon, and center it within the cam­era’s vie wfinder .Focus the image with the telescope’s f ocuser.
Try several exposure times, all less than 1 second, depending
on the phase of the moon and the ISO (film speed) of the film
being used. A remote shutter release is recommended, as
touching the camera’s shutter release can vibrate the camera
enough to ruin the exposure.

Planetary Photography

Once basic Moon photography has been mastered, it’s time to
get images of the planets.This type of astrophotography also
works to get highly magnified shots of the Moon.In addition to
the T-ring, you will need a Universal 1.25" Camera Adapter.
The TrueT rac k Motor Drive System (single or dual axis) is also
required. This is because a longer exposure is necessary,
which would cause the image to blur if no motor drive was
used for tracking.The equatorial mount must be accurately
polar aligned, too.

As before, connect the T-r ing to your camera. Before connect­ing the universal camera adapter to the T-r ing, an eyepiece
must be inserted and locked into the body of the universal
camera adapter.Start by using a medium-low po wer eyepiece
(about 25mm); you can increase the magnification later with a
high-power eyepiece. Then connect the entire camera
adapter, with eyepiece inside, to the T-ring. Insert the whole
system into the focuser and secure firmly with the thumb­screw.

Aim the telescope at the planet (or Moon) you wish to shoot.
The image will be highly magnified, so you may need to use
the finder scope to center it within the camera’s viewfinder.
Turn the motor drive on.Adjust the telescope’s f ocuser so that
the image appears sharp in the camera’s viewfinder .The cam­era’s shutter is now ready to be opened. A remote shutter
release must be used or the image will be blurred beyond
recognition. Try exposure times between 1 and 10 seconds,
depending upon the brightness of the planet to be pho­tographed and the ISO of the film being used.

“Piggyback Photography”

The Moon and planets are interesting targets for the budding
astrophotographer, but what next? Literally thousands of
deep-sky objects can be captured on film with a type of
astrophotography called “piggybacking”.The basic idea is that
the camera with its own camera lens attached rides on top of
the main telescope. The telescope and camera both move
with the rotation of the Earth when the mount is polar aligned
and the motor drive is engaged.This allows for a long expo­sure through the camera without having the object or back­ground stars blurred.In addition to the motor drive (dual-axis),
an illuminated reticle eyepiece is also needed.The T-ring and
camera adapter are not needed, since the camera is exposing
through its own lens. Any camera lens with a focal length
between 35mm and 400mm is appropriate.

Figure 14. Starhopping is a good way to locate hard-to-find

objects. Refer to a star chart to map a route to the object that uses
bright stars as guideposts. Center the first star you’ve chosen in the
finder scope and telescope eyepiece (1).Now move the scope
carefully in the direction of the next bright star (2), until it is
centered. Repeat (3 and 4). The last hop (5) should place the
desired object in the eyepiece.

On the top of one of the tube rings is a piggyback camera
adapter.This is the black knob with the threaded shaft pro­truding through it. The tube ring with the piggyback adapter
should be closest to the open end of the telescope tube.
Remove the tube rings from the equatorial mount and swap
their position if necessary. Now, connect the camera to the
piggyback adapter.There should be a 1/4"-20 mounting hole
in the bottom of the camera’s body. Thread the protruding
shaft of the piggyback adapter into the 1/4"-20 mounting hole
in the camera a few turns.Position the camera so it is parallel
with the telescope tube and turn the knurled black knob of the
piggyback adapter counter-clockwise until the camera is
locked into position.

Aim the telescope at a deep-sky object. It should be a fairly
large deep-sky object, as the camera lens will likely have a
wide field of view. Check to make sure that the object is also
centered in the camera’s viewfinder. Turn the motor dr ive on.
Now, look into the telescope’s eyepiece and center the bright­est star within the field of view. Remove the eyepiece and
insert the illuminated reticle eyepiece into the focuser draw­tube.Tur n the eyepiece’s illuminator on (dimly!). Recenter the
bright star (guide star) on the crosshairs of the reticle eye­piece. Check again to make sure that the object to be pho­tographed is still centered within the camera’s field of view.If it
is not, recenter it by repositioning the camera on the piggy­back adapter, or by moving the main telescope. If you move
the main telescope, then you will need to recenter another
guide star on the illuminated eyepiece’s crosshairs. Once the
object is centered in the camera and a guide star is centered
in the reticle eyepiece, you’re ready to shoot.

Deep-sky objects are quite faint, and typically require expo­sures on the order of 10 minutes.To hold the camera’s shutter
open this long, you will need a lock shutter release cable.Set
the camera’s shutter to the “B” (bulb) setting. Depress the
locking shutter release cable and lock it. You are now expos­ing your first deep-sky object.

While exposing through the camera lens, you will need to
monitor the accuracy of the mount’s tracking by looking
through the illuminated reticle eyepiece in the main telescope.
If the guide star drifts from its initial position, then use the
hand controller of the motor drive to “move” the guide star
back to the center of the crosshairs. Any drifting along the
Dec. axis is a result of improper polar alignment, so if the
guide star drifts greatly in Dec., the mount may need to be
polar aligned more accurately.

When the exposure is complete, unlock the shutter release
cable and close the camera’s shutter.

Astrophotography can be enjoyable and rewarding, as well as
frustrating and time-consuming. Star t slowly and consult out­side resources, such as books and magazines, for more
details about astrophotography. Remember ... have fun!

10. Collimating

(Aligning the Optics)

The SkyView Pro 100 EQ telescope has objective lens cell
which incorporates an optical alignment adjustment;this helps
to ensure peak optical performance. Collimating is the
process of aligning the telescope’s optics.In the case of the
SkyView Pro 100 EQ, collimating entails tilting the objective
lens assembly so that the optical axis is precisely parallel to
the telescope’s focuser.The telescope has been collimated at
the factory, so no adjustments to the lens cell are likely to be
necessary.If you are unsure or uncomfortable about making
optical alignment adjustments, we strongly recommend that
you just leave it alone.

Your SkyView Pro 100 EQ comes with a collimating tool.
Figure 15 shows the collimating tool in place.

Use of the collimating tool is best done during the day, either
outdoors or in a well-lit room.Point the telescope at a dark tar­get of uniform brightness, like a painted wall or a black piece
of construction paper.The distance of the target is unimpor­tant.You will also need a 2.5mm hex key and a Phillips-head
screwdriver.

1. Insert the collimating tool into the telescope’s focuser.You
will need to use the telescope’s 1.25" adapter in the
focuser. Secure the collimating tool in the focuser with the
thumbscrew on the 1.25" adapter.

2. Look into the viewing hole of the collimating tool.You are
now looking straight down the interior of the telescope
tube at the objective lens.

3. Loosen the secur ing thumbscrew, and rotate the collimat­ing tool until you can see the reflection of the of the tool’s

16

Figure 15. The collimating tool in the SkyView Pro 100 focuser.

1.25" adapter

Viewing hole

Reflective ring

17

reflective ring in the objective lens.To do this, you will need
to point the wide hole in the collimating tool’s body toward
a source of light. Ignoring the tiny central reflection, you
should see two separate reflections of the ring in the
objective lens.If you see only one reflection, then your tel­escope is already collimated.

4. Use the collimating screws in the lens cell to center the
reflections on top of one another (Figure 16). There are
three pairs of screws; each pair works together to tilt the
lens. Using your 2.5mm hex key and Phillips-head screw­driver, loosen one of the scre ws and then tighten the other
in the pair.Look into the viewing hole of the collimating tool
to see if the reflections have moved closer together or fur­ther apart. Once you get the reflections as close together
as you can get with one pair of screws, move on to anoth­er pair.

5. Continue making adjustments to each pair of screws until
the reflections are precisely centered on each other, which
will give the appearance of one ring. Once only one circu­lar ring is visible, no further collimation adjustments are
needed.

Your SkyView Pro 100 EQ is now collimated.You should not
need to align the optics again unless the telescope is roughly
handled.

11. Care and Maintenance

If you give your telescope reasonable care, it will last a life­time. Store it in a clean, dry, dust-free place, safe from rapid
changes in temperature and humidity. Do not store the tele­scope outdoors, although storage in a garage or shed is OK.
Small components like eyepieces and other accessories

should be kept in a protective box or storage case. Keep the
dust cover on the front of the telescope when not in use.

Your SkyView Pro 100 EQ requires very little mechanical
maintenance.The optical tube is aluminum and has a smooth
painted finish that is fairly scratch-resistant. If a scratch does
appear on the tube, it will not harm the telescope. Smudges
on the tube can be wiped off with a soft cloth and a household
cleaner such as Windex or Formula 409.

Cleaning Lenses

Any quality optical lens cleaning tissue and optical lens clean­ing fluid specifically designed for multi-coated optics can be
used to clean the exposed lenses of your telescope’s objec-
tive lens, eyepieces, or finder scope. Never use regular glass
cleaner or cleaning fluid designed for eyeglasses. Before
cleaning with fluid and tissue, however, blow any loose parti­cles off the lens with a blower bulb or compressed air.Then
apply some cleaning fluid to a tissue, never directly on the
optics.Wipe the lens gently in a circular motion, then remove
any excess fluid with a fresh lens tissue.Oily fingerprints and
smudges may be removed using this method. Use caution;
rubbing too hard may scratch the lens.For the objective lens,
clean only a small area at a time, using a fresh lens tissue on
each area. Never reuse tissues.

12. Specifications

Objective lens: Achromatic doublet, air-spaced
Objective lens coating: Multi-coated
Objective lens diameter: 100mm (3.9")
Focal Length: 600mm
Focal Ratio: f/6.0
Eyepieces: 25mm and 10mm Sirius Plössls, fully coated,

1.25"
Magnification: 24x (with 25mm) and 60x (with 10mm)
Finder Scope: 6x30 Achromatic, 7° field of view
Focuser: Rack and pinion, accepts 1.25" or 2" accessories

and camera T-Ring
Diagonal: 90° Star diagonal, mirror type, 1.25"
Mount: SkyView Pro, German equatorial
Tripod: Steel
Tripod support tray: Aluminum, provides additional stability,

holds five 1.25" eyepiece and two 2" eyepieces
Weight: 36 lbs. (Mount 30 lbs., optical tube 6 lbs.)
Polar axis latitude adjustment:8° to 70°
Polar axis finder: Optional
Motor Drives: Optional

Figure 16. The lens cell of the SkyView Pro 100.There are

three pairs of collimating screws; each pair of screws work together
to adjust the tilt of the lens.

Pair of

collimating

screws (3)

18

19

20

One-Year Limited Warranty

This Orion SkyView Pro 100 EQ is warranted against defects in materials or workmanship f or a
period of one year from the date of purchase.This warranty is for the benefit of the original retail
purchaser only. During this warranty period Orion Telescopes & Binoculars will repair or
replace, at Orion’s option, any warranted instrument that proves to be defective, provided it is
returned postage paid to: Orion Warranty Repair, 89 Hangar Way, Watsonville, CA 95076.If the
product is not registered, proof of purchase (such as a copy of the original invoice) is required.

This warranty does not apply if, in Orion’s judgment, the instrument has been abused, mishan-
dled, or modified, nor does it apply to normal wear and tear.This warranty gives you specific
legal rights, and you may also ha ve other rights, which vary from state to state.For further war­ranty service information, contact: Customer Service Department, Orion Telescopes &
Binoculars, P. O.Box 1815, Santa Cruz, CA 95061; [phone].

Orion Telescopes & Binoculars

Post Office Box 1815, Santa Cruz, CA 95061

Customer Support Help Line [phone] • Day or Evening