Celestron Celestar 8 User manual

1
CELESTAR
INSTRUCTION MANUAL

TABLE OF CONTENTS
INTRODUCTION......................................................................................................................................... 5
HOW TO USE THIS MANUAL ............................................................................................................................ 5
A WORD OF CAUTION...................................................................................................................................... 6
THE SCHMIDT-CASSEGRAIN OPTICAL SYSTEM ................................................................................................ 7
ASSEMBLING YOUR CELESTAR........................................................................................................... 8
UNPACKING YOUR CELESTAR 8/CELESTAR DELUXE 8 .................................................................................... 8
SETTING UP THE TRIPOD ....................................................................................................................... 10
ADJUSTING THE TRIPOD HEIGHT.................................................................................................................... 11
ATTACHING THE WEDGE TO THE TRIPOD......................................................................................... 11
SETTING UP THE WEDGPOD........................................................................................................................... 12
LATITUDE ADJUSTMENT................................................................................................................................. 12
ATTACHING THE CELESTAR TO THE WEDGE / WEDGPOD............................................................................... 12
INSTALLING THE FINDER................................................................................................................................13
ATTACHING THE FINDER BRACKET................................................................................................................ 14
ATTACHING THE FINDER TO THE BRACKET.................................................................................................... 15
REMOVING THE LENS CAP ............................................................................................................................. 15
INSTALLING THE VISUAL ACCESSORIES ......................................................................................................... 16
The Visual Back........................................................................................................................................ 16
The Star Diagonal..................................................................................................................................... 16
The Eyepieces ........................................................................................................................................... 17
MOVING THE TELESCOPE IN R.A. AND DEC.................................................................................................. 18
INSTALLING THE R.A. ENCODER.................................................................................................................... 18
ADVANCED ASTRO MASTER SETUP............................................................................................................... 21
TRANSPORTING YOUR CELESTAR/CELESTAR DELUXE 8................................................................................ 22
STORING YOUR CELESTAR/CELESTAR DELUXE 8 .......................................................................................... 22
TELESCOPE BASICS............................................................................................................................... 23
IMAGE ORIENTATION..................................................................................................................................... 23
FOCUSING...................................................................................................................................................... 24
ALIGNING THE FINDER................................................................................................................................... 24
YOUR FIRST LOOK......................................................................................................................................... 25
Daytime Observing ................................................................................................................................... 25
Nighttime Observing................................................................................................................................. 25
CALCULATING MAGNIFICATION ..................................................................................................................... 26
DETERMINING FIELD OF VIEW ....................................................................................................................... 27
GENERAL OBSERVING HINTS......................................................................................................................... 27
GENERAL PHOTOGRAPHY HINTS.................................................................................................................... 28
ASTRONOMY BASICS............................................................................................................................. 29
THE CELESTIAL COORDINATE SYSTEM.......................................................................................................... 29
MOTION OF THE STARS .................................................................................................................................. 30
POLAR ALIGNMENT ....................................................................................................................................... 31
Finding the Pole ....................................................................................................................................... 32
Latitude Scale Polar Alignment Method................................................................................................... 33
Pointing at Polaris Method of Polar Alignment....................................................................................... 33
Declination Drift Method of Polar Alignment.......................................................................................... 34
ALIGNING THE RA SETTING CIRCLE .............................................................................................................. 35
USING THE CELESTAR DRIVE ............................................................................................................ 37
POWERING UP THE DRIVE.............................................................................................................................. 37

Celestar Manual
3
Outlets....................................................................................................................................................... 38
The Hand Controller (Optional Accessory).............................................................................................. 38
NORTHERN/SOUTHERN HEMISPHERE OPERATION ......................................................................................... 39
CHANGING THE BATTERY .............................................................................................................................. 39
TROUBLE SHOOTING...................................................................................................................................... 39
USING THE CELESTAR DELUXE DRIVE........................................................................................... 40
POWERING UP THE DRIVE ..................................................................................................................... 40
TRACKING RATE SELECTION................................................................................................................ 41
PERIODIC ERROR CORRECTION ........................................................................................................... 41
THE HAND CONTROLLER............................................................................................................................... 43
DECLINATION MOTOR CLUTCH ADJUSTMENT ................................................................................ 43
REPLACING THE BATTERY.................................................................................................................... 44
NORTHERN/SOUTHERN HEMISPHERE OPERATION......................................................................... 45
CELESTIAL OBSERVING....................................................................................................................... 46
OBSERVING THE MOON ................................................................................................................................. 46
Lunar Observing Hints ............................................................................................................................. 46
OBSERVING THE PLANETS.............................................................................................................................. 46
Planetary Observing Hints ....................................................................................................................... 46
OBSERVING THE SUN..................................................................................................................................... 47
Solar Observing Hints............................................................................................................................... 47
OBSERVING DEEP SKY OBJECTS.................................................................................................................... 47
Using the Setting Circles .......................................................................................................................... 47
STAR HOPPING............................................................................................................................................... 48
SEEING CONDITIONS ...................................................................................................................................... 50
Transparency............................................................................................................................................ 50
Sky Illumination........................................................................................................................................ 50
Seeing........................................................................................................................................................ 50
CELESTIAL PHOTOGRAPHY............................................................................................................... 53
SHORT EXPOSURE PRIME FOCUS PHOTOGRAPHY .......................................................................................... 53
PIGGYBACK PHOTOGRAPHY........................................................................................................................... 54
EYEPIECE PROJECTION................................................................................................................................... 56
LONG EXPOSURE PRIME FOCUS PHOTOGRAPHY............................................................................................ 57
CCD IMAGING............................................................................................................................................ 60
FASTAR LENS ASSEMBLY OPTION -- USING YOUR CELESTAR DELUXE TELESCOPE AT F/1.95 WITH OPTIONAL
PIXCEL CCD CAMERA .................................................................................................................................. 60
DESCRIPTION OF F-NUMBERS......................................................................................................................... 61
FASTAR CONFIGURATIONS............................................................................................................................. 61
IMAGING AT F/1.95 ........................................................................................................................................ 61
IMAGING AT F/6.3 (MEDIUM SIZE TO SMALL GALAXIES)................................................................................. 62
IMAGING AT F/10 (LUNAR OR SMALL PLANETARY NEBULAE)......................................................................... 62
IMAGING AT F/20 (PLANETARY OR LUNAR).................................................................................................... 62
TELESCOPE MAINTENANCE............................................................................................................... 64
CARE AND CLEANING OF THE OPTICS ............................................................................................................ 64
COLLIMATION ................................................................................................................................................ 64
OPTIONAL ACCESSORIES.................................................................................................................... 66
THE MESSIER CATALOG...................................................................................................................... 73
LIST OF BRIGHT STARS........................................................................................................................ 77

Celestar Manual
4
TECHNICAL SPECIFICATIONS............................................................................................................ 78
FURTHER READING............................................................................................................................... 79

Celestar Manual
5
INTRODUCTION
Welcome to the Celestron world of amateur astronomy! For more than a quarter of a century, Celestron
has provided amateur astronomers with the tools needed to explore the universe. The Celestar line of
telescopes continue in this proud tradition combining large aperture optics with ease of use and portability.
With a mirror diameter of 8 inches, your Celestar telescope has a light gathering power of 841 times that of
the unaided human eye. Yet despite its large aperture, the Celestar optical system is extremely compact
and portable because it utilizes the Schmidt-Cassegrain design. This means you can take your Celestar
telescope to the mountains or desert or wherever you observe.
The Celestar telescope is made of the highest quality materials to ensure stability and durability. All this
adds up to a telescope that gives you a lifetime of pleasure with a minimal amount of maintenance. And,
your Celestar telescope is versatile −it grows as your interest in astronomy grows.
Your Celestar telescope however, is not limited to astronomical usage alone. It can also be used for
terrestrial viewing to study the world around you. All you need to do is take the time to familiarize
yourself with your Celestron telescope and its operation.
HOW TO USE THIS MANUAL
This manual is designed to instruct you in the proper use of your Celestar telescope. The instructions are
for assembly, initial use, long term operation, and maintenance. There are seven major sections to the
manual. The first section covers the proper procedure for setting up your Celestar telescope. This includes
setting up the tripod, attaching the telescope to the mount, balancing the telescope, etc.
The second section deals with the basics of telescope use. Topics include focusing, aligning the finder, and
taking your first look. The third section deals with the basics of astronomy which includes the celestial
coordinate system, the motions of the stars, and polar alignment. The fourth section deals with celestial
observing covering visual observations of the planets and deep-sky objects. Using both the setting circles
and star hopping are discussed. The fifth section covers celestial photography working from the easiest to
the most difficult. The last major section is on telescope maintenance, specifically on cleaning and
collimation. Keeping your Celestar telescope in proper collimation is the single most important thing you
can do to ensure it performs well.
In addition to the major sections mentioned previously, there is a list of optional accessories for your
Celestar telescope that include a brief description of its purpose. This is the section to consult when you’ve
mastered the basics and ready for new, more challenging observations. The final part of this manual
contains a list of objects that can be observed through your Celestar telescope. Included are the
coordinates for each object, its brightness, and a code which indicates what type of an object it is. In
addition, there is a list of bright stars used for aligning the setting circles.
Read the assembly instructions through completely before you attempt to set up your Celestar telescope.
Then, once you’ve set up your Celestar telescope read the section on ‘Telescope Basics’ before you take it
outside and use it. This will ensure that you are familiar with your telescope before you try to use it under
a dark sky. Since it will take a few observing sessions to familiarize yourself with your Celestar telescope
you should keep this manual handy until you have fully mastered your telescope’s operation. After that,
save the manual for future reference.

Celestar Manual
6
A WORD OF CAUTION
Your Celestar telescope is designed to give you hours of fun and rewarding observations. There are,
however, a few things to consider before using your telescope that will ensure your safety and protect your
equipment.
WARNING ! NEVER LOOK DIRECTLY AT THE SUN WITH THE NAKED EYE OR WITH A
TELESCOPE. PERMANENT AND IRREVERSIBLE EYE DAMAGE MAY RESULT.
NEVER USE YOUR TELESCOPE TO PROJECT AN IMAGE OF THE SUN ONTO ANY SURFACE.
INTERNAL HEAT BUILD-UP CAN DAMAGE THE TELESCOPE AND/OR ANY ACCESSORIES
ATTACHED TO IT.
NEVER USE AN EYEPIECE SOLAR FILTER OR A HERSCHEL WEDGE. INTERNAL HEAT
BUILD-UP INSIDE THE TELESCOPE CAN CAUSE THESE DEVICES TO CRACK OR BREAK,
ALLOWING UNFILTERED SUNLIGHT TO PASS THROUGH TO THE EYE.
NEVER LEAVE THE TELESCOPE UNSUPERVISED, EITHER WHEN CHILDREN ARE PRESENT
OR WITH ADULTS WHO MAY NOT BE FAMILIAR WITH THE CORRECT OPERATING
PROCEDURES OF YOUR TELESCOPE.
NEVER POINT YOUR TELESCOPE AT THE SUN UNLESS YOU HAVE THE PROPER SOLAR
FILTER. WHEN USING YOUR TELESCOPE WITH THE CORRECT SOLAR FILTER, ALWAYS
COVER THE FINDER. ALTHOUGH SMALL IN APERTURE, THIS INSTRUMENT HAS ENOUGH
LIGHT GATHERING POWER TO CAUSE PERMANENT AND IRREVERSIBLE EYE DAMAGE. IN
ADDITION, THE IMAGE PROJECTED BY THE FINDER IS HOT ENOUGH TO BURN SKIN OR
CLOTHING.

Celestar Manual
7
THE SCHMIDT-CASSEGRAIN OPTICAL SYSTEM
A telescope is nothing more than an instrument that collects and focuses light. The nature of the optical
design determines how the light is focused. Some telescopes, known as refractors, use lenses while others,
known as reflectors, use mirrors. The Schmidt-Cassegrain optical (or Schmidt-Cass for short) system uses
a combination of mirrors and lenses and is referred to as a compound or catadioptric telescope. This
unique design offers large diameter optics while maintaining very short tube lengths, making them
extremely portable. This makes them extremely popular among amateur astronomers. The Schmidt-
Cassegrain system consists of a zero power corrector plate, a spherical primary mirror, and a secondary
mirror. Once light rays enter the optical system, they travel the length of the optical tube three times.
Inside the optical tube you will notice a black tube (not illustrated) that extends out from the center hole in
the primary mirror. This is the primary baffle tube which prevents stray light from passing through to the
eyepiece or camera without striking the primary or secondary mirrors.
Figure 1-1. This cross-section diagram shows the light path of the Schmidt-Cassegrain optical
system. Note that the light rays travel the length of the telescope tube three times, making this a
compact design. Note that the curve of the corrector plate is greatly exaggerated.

Celestar Manual
Assembling your Celestar8
ASSEMBLING YOUR CELESTAR
The complete line of Celestar models are fork mounted telescopes with built-in single motor gear drives.
The Celestar 8 and Celestar 8 computerized have a spur gear drive powered by a single 9-volt battery while
the Celestar Deluxe 8 and Celestar Deluxe 8 computerized are worm gear driven powered by two 9-volt
batteries. All models can also run off external AC or DC power. All come standard with the Starbright™
coating, an enhanced multilayer aluminum coating on the primary and secondary mirrors for increased
reflectivity. Also, the corrector is fully coated to allow maximum light transmission.
The Celestar 8’s are shipped in two boxes. One contains the standard Wedgpod, a combination wedge and
tripod. One contains the telescope with all the standard accessories, which are:
•25mm SMA Ocular 1-1/4"
•Visual Back 1-1/4"
•Star Diagonal 1-1/4"
•6x30mm Finder With Bracket
•Lens Cap
•9-volt Alkaline Battery
•Bolt Pack
The Celestar Deluxe 8’s are shipped in four boxes. The telescope, the standard wedge, and the standard
adjustable height tripod each are contained in its own box. And one box contains all the standard
accessories, which are:
•26mm Plössl Ocular 1-1/4”
•Visual Back 1-1/4”
•Star Diagonal 1-1/4”
•9x50mm Finder with Bracket
•Hand Controller with cable
•Car Battery Adapter
•Two 9-volt Alkaline Batteries (packaged with telescope)
•Lens Cap (packaged with telescope)
•Declination motor with cable (packaged with telescope)
In addition to the above listed accessories, the computerized models also come with standard optical
encoders and an Advanced Astro Master®. This unit is installed on the fork mount and is virtually ready to
use.
UNPACKING YOUR CELESTAR 8/CELESTAR DELUXE 8
Remove the Wedgpod (or the wedge and tripod), the telescope, and the standard accessories from their
respective boxes. Save the boxes since you may want to ship your telescope via a common carrier at some
time in the future. To assemble the Celestar 8, you will need a 3/16” and a 5/16” Allen wrench and a
Phillips screw driver.
Use the diagram on the following page (Figure 2-1, Figure 2-2) to familiarize yourself with the various
parts of your Celestar telescope.
The Computerized models are identical with the exception that the Advanced Astro Master comes installed.

Celestar Manual
Assembling your Celestar 9
Figure 2-1 -- Celestar 8
Figure 2-2 -- Celestar8 Deluxe

Celestar Manual
Assembling your Celestar10
SETTING UP THE TRIPOD
(For Celestar Deluxe 8 And Celestar Deluxe 8 Computerized Only)
For maximum rigidity, the Celestron field tripod has a leg support bracket. This bracket fits snugly against
the tripod legs, increasing stability while reducing vibration and flexure. However, the tripod is shipped
with each arm of the leg support bracket in between the legs so the tripod legs can collapse. To set up the
tripod:
1. Hold the tripod with the head up and the legs pointed toward the ground.
2. Pull the legs away from the central column until they will not separate any further. A small stop on the
top of each tripod leg presses against the tripod head to indicate maximum separation.
3. Rotate the tension knob (located underneath the support bracket on the central column) clockwise until
it is close to the bottom of the central column.
4. Turn the leg support bracket until the cups on the end of each bracket are directly underneath each leg.
5. Rotate the tension knob counterclockwise until the bracket is secure against the tripod legs. Do not
over tighten.
The tripod will now stand by itself. Once the wedge and telescope are attached to the tripod, readjust the
tension knob to ensure that the leg support bracket is snug. Once again, do not over tighten!
Figure 2-3
Tripod Head
Central Column
Leg Support Bracket
Tension Knob
Leg Clamp

Celestar Manual
Assembling your Celestar 11
ADJUSTING THE TRIPOD HEIGHT
(For Celestar Deluxe 8 And Celestar Deluxe 8 Computerized Only)
The tripod that comes with your Celestar Deluxe 8 telescope is adjustable. To adjust the height at which
the tripod stands:
1. Loosen the extension clamp on one of the tripod legs (see figure 2-3).
2. Extend the leg to the desired height.
3. Tighten the extension clamp to hold the leg in place.
4. Repeat this process for each of the remaining legs.
You can do this while the tripod legs are still folded together.
Remember that the higher the tripod legs are extended, the less stable it is. For casual observing, this may
not pose a problem. However, if you plan on doing photography, the tripod should be set low to ensure
stability. A recommended height is to set the tripod in such a manner that you can look directly into the
eyepiece on the telescope with a diagonal while seated.
ATTACHING THE WEDGE TO THE TRIPOD
(For Celestar Deluxe 8 And Celestar Deluxe 8 Computerized Only)
Your Celestar Deluxe 8 telescope has a clock drive built into the base to track the stars as they move across
the sky from east to west. However, for this drive to be useful, the telescope’s axis of rotation should be
made parallel to the Earth’s axis. The wedge, which comes standard with both telescopes, allows you to
tilt the telescope’s axis of rotation. This process is known as polar alignment and is described in the
section by the same name. The wedge, like the tripod, is fully assembled and only needs to be attached to
the tripod.
The tripod has six holes on its base for mounting equipment. Three of the holes are threaded with 5/16-18
threads and three of the holes are open. The three open holes are for mounting a different telescope in the
Celestron line. To mount a wedge to the tripod, the three threaded holes are used.
To attach the wedge to the tripod:
1. Place the three slots on the wedge over the three threaded holes in the tripod head.
2. Thread the three 5/16-18x1” socket head cap screws and washers into the holes until tight (see figure
2-5)
3. Tighten the screws until the wedge cannot be moved side to side. These can be loosened later for
polar alignment.

Celestar Manual
Assembling your Celestar12
Wedge
Bolts
Threaded Holes
Tripod
Figure 2-4
SETTING UP THE WEDGPOD
(For Celestar 8 And Celestar 8 Computerized Only)
The Wedgpod comes pre-assembled. Just remove it from the box, stand it up, and separate the tripod legs.
There are stops that set the proper angle of the legs.
LATITUDE ADJUSTMENT
Before attaching the telescope to the wedge/Wedgpod, you must adjust the wedge/Wedgpod to the proper
latitude. To do so:
1. Loosen the four socket head screws that hold the tilt plat in place. They are located on the side plates
of the wedge (two on each side). You’ll need a 3/16” Allen wrench.
2. Move the tilt plate until the latitude scale indicates the latitude of your observing site. The latitude
scale is on the side plate. The center of the bolt serves as the marker.
3. Tighten the socket head screws on the side plates to hold the tilt plate in place.
You are now ready to attach the telescope to the wedge/Wedgpod.
ATTACHING THE CELESTAR TO THE WEDGE / WEDGPOD
For astronomical viewing, you should mount the telescope on the wedge/wedgpod. This will allow you to
polar align the telescope, use the setting circles and the clock drive. To mount the telescope on the wedge:

Celestar Manual
Assembling your Celestar 13
1. Lay the telescope on its side and locate the three threaded holes in the bottom of the drive base.
2. Partially thread one of the three 3/8"-16 bolts (supplied in the bolt pack) into the hole that is opposite
the rectangular portion of the base.
3. Pick the telescope up by the fork tines and position it above the tripod. It should be oriented so that
the telescope is over the tripod with the base pointing toward the tilt plate.
4. Slide the bolt into the slot on the top of the tilt plate.
Figure 2-5
1. Tighten the bolt slightly so that the bottom of the drive base is flush to the tilt plate. Do not tighten it
fully or you will not be able to move the base enough to insert the two remaining bolts. If you do not
tighten the bolt at all, the drive base may be tilted slightly preventing the remaining two bolts from
threading straight in.
2. Move the base of the telescope until the two remaining holes in the drive base line up with the holes in
the tilt plate on the wedge.
3. Insert the screws and tighten all three completely.
4. There is no need to loosen these until you are ready to remove the telescope from the wedge/wedgpod.
INSTALLING THE FINDER
The Celestar 8 comes with a 6x30 finderscope which has an 7° field-of-view. The Celestar Deluxe 8
comes with a 9x50 finder, which has a 5.8° field of view. The specifications for a finderscope, 6x30 or
Drive Base
3/8”-16 Bolt
Slot
Tilt Plate

Celestar Manual
Assembling your Celestar14
9x50, stand for the magnification and the aperture, in millimeters, of the scope. So, a 6x30 finder
magnifies six times and has a 30mm objective lens.
To ensure that the finder and bracket are not damaged during shipping, they are not attached to the
telescope at the factory. Start by removing the finder and hardware from the plastic wrapper. Included are
the following:
Celestar 8
•6x30mm Finderscope
•Rubber O-Ring
•Three Nylon Thumbscrews (10-24x1/2)
•Two Phillips Pan Head Screws (10-24x5/8)
Celestar Deluxe 8
•9x50mm Finderscope
•Rubber O-Ring
•Three Nylon Thumbscrews (10-24x1/2)
•Two Phillips Pan Head Screws (10-24x5/8")
Mounting the finder is a two-step process and is the same for the Celestar 8 and the Celestar Deluxe 8.
First you mount the bracket to the telescope, then mount the finder in the bracket.
ATTACHING THE FINDER BRACKET
1. Locate the two holes in the rear cell of the telescope just left of center (when looking from the back of
the tube).
2. Remove the tape covering the two holes. The tape prevents dust and moisture from entering the
optical tube before installing the finder.
3. Place the finder bracket over the holes. Orient the bracket so that the ring with the holes for the
adjustment screws is closer to the rear cell of the telescope (see Figure 2-6).
4. Thread the screws in by hand and then tighten with a Phillips screw driver.
Figure 2-6

Celestar Manual
Assembling your Celestar 15
ATTACHING THE FINDER TO THE BRACKET
With the bracket firmly attached to the telescope, you are ready to attach the finder to the bracket.
1. Thread the three nylon thumbscrews into the finder bracket. Tighten the screws until the heads are
flush with the inner diameter of the bracket ring. Do not thread them in completely or they will
interfere with the placement of the finder.
2. Slide the rubber O-ring onto the back (i.e., eyepiece end) of the finder. It may need to be stretched a
little.
3. Position the O-ring on the main body of the finder so that it is toward the front (i.e., objective) end of
the finder.
4. Slide the end of the finder where the eyepiece mounts into the front of the bracket. Push it back until
the end of the finder, where the eyepiece attaches, is past the back ring of the bracket , but NOT so far
that the O-Ring is snug inside the back ring.
5. Slide the O-Ring toward the back(i.e., eyepiece end) of the finder.
6. Push the finder back until the O-Ring is snug inside the back ring of the finder bracket.
7. Hand tighten the three nylon-tipped thumbscrews until snug.
To properly align the finder, please see the section on “Aligning the Finder.”
Figure 2-7
REMOVING THE LENS CAP
The Celestar lens cap utilizes a bayonet-type locking mechanism to hold it in place. To remove the lens
cap, hold the cover firmly and rotate the outer edge 1/2" counterclockwise and pull off.

Celestar Manual
Assembling your Celestar16
INSTALLING THE VISUAL ACCESSORIES
Installing the ocular and other visual accessories is the same for both the Celestar 8 and Celestar Deluxe 8.
The Visual Back
The visual back allows you to attach most visual accessories to the telescope. If you use a 1-1/4" star
diagonal or if you want to insert the eyepiece into the telescope without a diagonal, then attach the visual
back to the rear cell on the back of the telescope (see Figure 2-8). To attach the visual back:
1. Remove the protective cap from the back of your telescope. It is pressed onto the rear cell.
2. Place the slip ring on the visual back over the threads on the rear cell.
3. Tighten by rotating the slip ring clockwise until tight.
Once this is done, you are ready to attach other accessories such as eyepieces, and diagonal prisms. If you
want to remove the visual back, rotate the slip ring counterclockwise until it is free of the rear cell.
The Star Diagonal
The star diagonal is a prism
that diverts the light at a
right angle from the light
path of the telescope. For
astronomical observing, this
allows you to observe in
positions that are more
comfortable than if you were
to look straight through. To
attach the star diagonal:
1. Turn the thumbscrew on
the visual back until its
tip no longer extends
into (i.e., obstructs) the
inner diameter of the
visual back.
Figure 2-8
2. Slide the chrome portion of the star diagonal into the visual back.
3. Tighten the thumbscrew on the visual back to hold the star diagonal in place.
If you wish to change the orientation of the star diagonal, loosen the thumbscrew on the visual back until
the diagonal rotates freely. Rotate the diagonal to the desired position and tighten the thumbscrew.

Celestar Manual
Assembling your Celestar 17
The Eyepieces
The eyepiece, or ocular, is the optical element that
magnifies the image focused by the telescope.
The eyepiece fits either into the visual back
directly or into the star diagonal. To install an
eyepiece:
1. Loosen the thumbscrew on the star diagonal
so that it does not obstruct the inner diameter
of the eyepiece end of the diagonal.
2. Slide the chrome portion of the eyepiece into
the star diagonal.
3. Tighten the thumbscrew on the diagonal to
hold the eyepiece in place.
To remove the eyepiece, loosen the thumbscrew
on the star diagonal and slide the eyepiece out.
In addition to barrel diameter, eyepieces are also referred to in terms of their focal length. The focal length
of each eyepiece is printed on the eyepiece barrel. The longer the focal length (i.e., the larger the number),
the lower the eyepiece power and the shorter the focal length (i.e., the smaller the number), the higher the
magnification. Generally, you will use low-to-moderate power when viewing. For more information on
how to determine power, see the section on “Calculating Magnification.”
Barrel diameter is the diameter of the barrel that slides into the star diagonal. Standard barrel diameters are
.96”, 1.25”, and 2”. The Celestar 8 and Celestar Deluxe 8 come standard for use with 1.25” barrel
eyepieces.
Figure 2-9

Celestar Manual
Assembling your Celestar18
MOVING THE TELESCOPE IN R.A. AND DEC
Pointing the telescope is done by moving the telescope in right ascension, or R.A. for short, and
declination, or DEC for short (see Figure 2-11). Right ascension corresponds to east/west movement while
declination corresponds to north/south movement. To make considerable directional changes:
1. Loosen the R.A. and DEC clamps on the mount.
2. Move the telescope until pointing in the desired direction.
3. Lock the R.A. and DEC clamps to hold the telescope in place.
For fine adjustment in declination, simply turn the declination slow
motion knob. The DEC clamp does NOT have to be loosened. Once
you have the desired target, stop rotating the DEC slow motion knob. If
the DEC slow motion knob will not turn, the DEC travel arm may have
reached the end of the threaded rod. To correct this, rotate the DEC
slow motion knob in the opposite direction until the travel arm is in the
center of the fork tine (see figure 2-10). Release the DEC clamp and
manually center the object you were looking at. Tighten the DEC
clamp and the DEC slow motion knob will again allow fine adjustments
in both directions. The Celestar Deluxe is equipped with a standard
DEC motor for vibration free fine adjustment. Refer to the section
“Using The Celestar Deluxe Drive” in this manual for information on
operation and maintenance of the DEC motor.
For fine adjustments in right ascension, release the R.A. clamp until the R.A. slow motion knob rotates
freely. Turn the R.A. slow motion knob until the desired object is centered. Once centered, tighten the
R.A. clamp by turning it clockwise. The clamp must be sufficiently locked for the drive motors to engage
and move the telescope.
WARNING: DO NOT TURN THE R.A. SLOW MOTION KNOB WHEN THE R.A. CLAMP IS
IN THE FULLY LOCKED POSITION. DO NOT FORCE THE FORK MOUNT TO SWIVEL
WHEN THE R.A. CLAMP IS FULLY ENGAGED.
The telescope comes equipped with setting circles to help you locate
objects in the night sky. The DEC setting circle is in degree increments
while the R.A. setting circle is in hour and minute increments with a
marker every five minutes. The numbers on the inner circle are for the
northern hemisphere while those on the outer circle are for the southern
hemisphere.
INSTALLING THE R.A. ENCODER
(Celestar 8 Computerized and
Celestar Deluxe 8 Computerized Only)
The Celestar 8 Computerized and the Celestar Deluxe 8 Computerized
are identical to the Celestar 8 and the Celestar Deluxe 8 with the
exception that they comes with the Advanced Astro Master attached.
The Advanced Astro Master is fully installed and tested at the factory.
The R.A. encoder is removed in order for the telescope to be placed in
Figure 2-10
Figure 2-11

Celestar Manual
Assembling your Celestar 19
the storage position. Here is how to install the R.A. encoder (please refer to Figure 2-12 and Figure 2-13
for all installation procedures):
1. Swing the telescope through the fork tines so that it is pointing straight up.
2. Slide the R.A. encoder shaft through the hole in the R.A. encoder bracket (i.e., the long, flat bracket).
3. Place the lock washer and nut over the encoder shaft and tighten fully. This will hold the encoder to
the bracket.
4. Slide the R.A. encoder shaft into the R.A. encoder coupling screw (Celestar 8) or the hollow bolt
(Celestar Deluxe 8). Tighten the #6-32x5/16" socket set screw on the side of the R.A. encoder
coupling screw/hollow bolt to hold the R.A. encoder shaft in place.
5. For the Celestar Deluxe 8, place the slotted end of the R.A. bracket over the threaded cylindrical
spacer and insert the 8-32x1/4” screw into the threaded cylindrical spacer. Tighten the screw to hold
the bracket in place (refer to figure 2-12).
Figure 2-12
6. For the Celestar 8, place the slotted end of the R.A. bracket over the hollow cylindrical spacer and
insert the 8-32x1” screw through the spacer and thread it into the threaded hole on the fork. Tighten
the screw to hold the bracket in place (refer to Figure 2-13).
R.A. Encoder
R.A. Encoder Bracket
R.A. Encoder Nut
Hollow Bolt
6-32 Socket Set Screw
8-32 Phillips Pan
Head Screw
Washer
Spacer

Celestar Manual
Assembling your Celestar20
Figure 2-13
The installation of the R.A. encoder of the Advanced Astro Master is now complete. Keep in mind that the
R.A. encoder must be removed when returning the telescope to the storage position. Now connect the blue
connector on the cable to the five pins on the R.A. encoder, plug the phone jack type connector to the
Advanced Astro Master module, and the telescope is ready for hours of observing fun.
Please see the Advanced Astro Master instruction manual for complete operational information.
R.A. Encoder
Encoder Bracket
Encoder Lock Nut
Knurled R.A. Coupling
Screw
6-32 Socket Set Screw
Washer
8-32 Phillips
Pan Head
Spacer