Celestron STAR HOPPER User manual

STAR HOPPER®
INSTRUCTION MANUAL

1
TABLE OF CONTENTS
INTRODUCTION ................................................................................................. 2
Diagram of Star Hopper®4½................................................................................. 4
Diagram of Star Hopper®6 & 8 ............................................................................ 5
GLOSSARY ........................................................................................................... 6
UNPACKING the Star Hopper®6 and 8 ............................................................ 7
ASSEMBLY of the Star Hopper®6 and 8 .......................................................... 7
Assembling the Mounting ........................................................................................ 7
Assembling the Optical Tube .................................................................................. 9
Mounting the Primary Mirror ................................................................................. 10
BALANCING THE TELESCOPE ...................................................................... 10
INSTALLING OPTIONAL FINDERSCOPES ................................................. 11
COLLIMATION ................................................................................................... 12
Aligning the Secondary Mirror ............................................................................... 12
Aligning the Primary Mirror ................................................................................... 12
NIGHT TIME STAR COLLIMATING ............................................................. 12
TELESCOPE BASICS ......................................................................................... 15
Focusing the Telescope ........................................................................................... 15
Pointing the Telescope ............................................................................................ 15
Calculating Magnification ...................................................................................... 15
Determining Field of View ..................................................................................... 15
CELESTIAL OBSERVING ................................................................................ 16
Observing the Moon ............................................................................................... 16
Observing the Planets ............................................................................................ 16
Observing the Sun .................................................................................................. 17
Observing Deep-Sky Objects .................................................................................. 17
Star Hopping .......................................................................................................... 17
"SEEING CONDITIONS"................................................................................. 19
Transparency .......................................................................................................... 19
Sky Illumination ...................................................................................................... 19
Seeing ...................................................................................................................... 20
CLEANING THE OPTICS ................................................................................. 21
TECHNICAL SPECIFICATIONS ..................................................................... 22
OPTIONAL ACCESSORIES .............................................................................. 23

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INTRODUCTION
Congratulations on your purchase and welcome to the Celestron world of astronomy. If you’re a newcomer to the
hobby of astronomy, some of the terms and telescope components described in this instruction manual may be new
to you. To assist you in assembling and operating your telescope, the next few pages will explain some commonly
used terms and show diagrams of your new telescope and its components. If you’re already well-versed in the
language of astronomy and telescopes, you might want to review these sections, then move on to unpacking and
assembling your new Celestron telescope.
Please note that the Star Hopper® 4½comes pre-assembled, so the sections that will be most useful to you initially
are about setting your telescope up for use, including:
Balancing the telescope - page 10
Collimation - pages 12-13
Telescope basics - pages 15
You’ll also find this instruction manual contains a wealth of useful information on celestial observing, commonly
used terms in astronomy, instruction on the care of your telescope, and optional accessories to enhance your
viewing experience.
Celestron’s Star Hopper® Dobsonians are designed for beginners, yet they include advanced features that even
an experienced observer will appreciate. Below is an overview of these features, followed by more detailed
information in the next section.
•
••
•Balance Systems
Star Hoppers provide smooth, low friction altitude movement, allowing quick and easy balancing when using
optional accessories, such as heavier oculars or finderscopes. Without proper balance, such fine aiming
adjustments as centering an object in a high power eyepiece are difficult. Celestron is the only company to offer
an adjustable counterbalance system standard on its Dobsonian telescopes. In addition, the telescope tube ring on
the Star Hopper® 4½allows for rotation of the telescope tube in a circular motion, for easy adjustment while
observing.
•
••
•Optics
The Star Hopper® 4½mirror cell is carefully designed to support the telescope’s optical elements, without
stressing or pinching them, a common source of image distortion with other designs. This system keeps the optics
clean and the low mass primary mirror means cool down time is short.
The Star Hopper® 6 and 8 feature Celestron’s V-Spectrum LTM (low thermal mass) Optical System. This
system includes a unique molded Pyrex mirror, multicoated for increased reflectivity. It’s mounted on the
Pinnacle mirror cell and provides superior optical and thermal qualities.
The V- Spectrum LTM mirror is manufactured and hand figured to reach the optimal marriage of weight to
optical surface, resulting in a mirror with 40% less mass than traditional mirrors. Reduced mass lowers the “cool
down” period required to bring the mirror to ambient temperature, leaving more time for observing.

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The Pinnacle mirror cell features a mirror adjustment system that allows for fast collimation when using the
supplied collimation tool.
Our unique and heavy duty, single vane secondary mirror bracket creates minimal obstruction. This allows more
light to reach the primary mirror, which in turn provides a brighter image and better resolution.
•
••
•Inner Diameter Tubes
Celestron’s Star Hopper® Dobsonians (6"and 8") have their primary mirrors housed in oversized, flat black,
anti-reflective painted tubes, which reduce light scatter and tube currents, increasing image sharpness. These large
telescope tubes also increase image contrast and improve “seeing” when viewing planets and the moon.
Rack and Pinion Focuser
The Star Hoppers use a Rack and Pinion focuser which accepts 11/4" oculars. This type of focuser is more
convenient to use than helical focusers, which many other Dobsonians feature.
CAUTION: READ THIS SECTION BEFORE USING YOUR TELESCOPE
Your Celestron Star Hopper® telescope is designed to give you hours of fun and rewarding observations.
However, there are a few things to be aware of before using your telescope that will ensure your safety and protect
your equipment.
NEVER LOOK DIRECTLY AT THE SUN WITH THE NAKED EYE OR WITH A TELESCOPE. NEVER
POINT YOUR TELESCOPE AT THE SUN UNLESS YOU ARE USING THE PROPER SOLAR FILTER.
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 THAT
MAY BE ATTACHED TO IT.
NEVER LEAVE YOUR TELESCOPE UNSUPERVISED, ESPECIALLY WHEN CHILDREN ARE PRESENT.
THIS ALSO HOLDS TRUE FOR ADULTS WHO MAY NOT BE FAMILIAR WITH THE CORRECT
OPERATING PROCEDURES FOR YOUR TELESCOPE.
NEVER USE AN EYEPIECE SOLAR FILTER OR A HERSCHEL WEDGE. INTERNAL HEAT BUILD-UP
WITHIN THE TELESCOPE CAN CAUSE THESE DEVICES TO CRACK, BREAK OR DAMAGE YOUR
TELESCOPE. ANY SOLAR FILTER USED SHOULD BE A FILTER FOR THE PRIMARY LENS, SUCH AS
CELESTRON’S SOLAR SKREEN (SEE OPTIONAL ACCESSORIES ON PAGES 23- 24 ).
ALWAYS COVER A FINDERSCOPE (IF INSTALLED) WHEN USING YOUR TELESCOPE WITH THE
CORRECT SOLAR FILTER. ALTHOUGH SMALL IN APERTURE, THIS INSTRUMENT HAS ENOUGH
LIGHT GATHERING POWER TO CAUSE PERMANENT AND IRREVERSIBLE EYE DAMAGE. THE
IMAGE PROJECTED BY THE FINDERSCOPE IS HOT ENOUGH TO BURN SKIN OR CLOTHING.

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Star Hopper® 4 1/2
Finderscope
Clutch Tension Screw
Mount
Focuser
Eyepiece
Tube Ring
Altitude Bearing

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Star Hopper®6 and 8
E
y
e
p
iece
Focuser
Telescope
Tube
Altitude
Bearing
Lockin
g
Bolt
Dobsonian
Mount

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GLOSSARY
Altazimuth mount - the simplest type of mount, with two motions: altitude (up and down) and azimuth (side-to-
side). “Mount” refers to the parts of the telescope supporting the tube, which carries all the telescope’s optics. The
mount is made up of the ground plate, or base, and the rocker box.
Altitude clutch adjustment screw - used on the Star Hopper 4½to adjust the clutch tension on the altitude axis.
Altitude hubs - used on the Star Hopper 6and 8 to provide an axis of rotation for altitude adjustments.
Aperture - the diameter of the main optical element of the telescope; either the primary mirror or objective lens.
The larger the aperture, the more light the telescope collects. More light creates a brighter, sharper image.
Barlow lens - these lenses are optional accessories that double the magnifying power of your eyepieces by
increasing their effective focal length. For example, an 18mm eyepiece mounted on a 2x Barlow lens would have
the magnifying power of a 9mm eyepiece. It’s like having two eyepieces in one - an economical way to increase
your range of magnifications without buying new eyepieces.
Collimation - the proper alignment of the optical elements in a telescope, which is critical to achieving optimum
results. Poor collimation results in visual aberrations and distorted images. A full description of how to collimate
your telescope follows on pages 12 - 14.
Collimation cap - a tool for aligning the optics in a telescope. The optics to be aligned in the Star Hopper
telescopes are the primary mirror and the secondary mirror.
Deep-sky objects - celestial objects outside the boundaries of our solar system.
Dobsonian telescope - simple, azimuth mounted Newtonian telescope.
Extended objects - large celestial objects, other than stars, such as nebulae and galaxies.
Field of view - the size, in degrees, of the area you can see through the eyepiece of your telescope.
Finderscope - a low power telescope with cross hairs mounted to the side of a higher powered telescope, used to
locate objects more easily.
Focal length - the distance from the optical center of the lens to the point where the incoming light rays converge,
creating a clear, focused image.
Inner diameter - the measured diameter of the inside of the telescope tube.
Newtonian reflecting telescope - generally use a concave parabolic primary mirror to collect and focus incoming
light into a flat secondary mirror, which reflects the image into the eyepiece.
Off-axis coma - associated mainly with parabolic reflector telescopes, this is a blur caused by the spherical
aberration of oblique rays of light passing through a lens. The blur will be more pronounced near the edges of the
field of view and have a V-shaped appearance.
Pinnacle mirror cell - a stress free support for the primary mirror, made of aluminum to conduct heat away from
the mirror for quicker “cool down” time. The cell is designed to allow air flow within the telescope tube, assisting
the entire system to reach thermal equilibrium rapidly.
Primary mirror - gathers incoming light and forms a sharply focused image of the object being viewed.
Refracting telescope - a long, thin tube in which light passes in a straight line from the front objective lens
directly to the eyepiece at the opposite end of the tube.
Secondary mirror - reflects light from the primary mirror to the eyepiece. It’s also know as a diagonal mirror
because it is at 45°with respect to the optical axis.
“Seeing” or “seeing conditions” - refer to the stability of the atmosphere, transparency and sky illumination. See
pages 20 and 21 for a full description.
Thermal turbulence - turbulence caused by temperature variations. Some sources are differences in temperature
between the telescope tube and the air within it, or viewing near a heat source, such as a parking lot releasing
stored daytime heat.
Tube currents - convection currents within the telescope caused by differences in temperature between the air and
the telescope tube. These currents form near the wall of the telescope tube, therefore the Star Hopper’s oversized
tube is very beneficial in reducing interference caused by currents.
V-Spectrum Low Thermal Mass Optical System - a unique Celestron optical system utilizing a molded Pyrex
mirror for reduced thermal mass, in conjunction with the pinnacle mirror cell (see above).

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INSTRUCTIONS FOR UNPACKING AND ASSEMBLING
STAR HOPPER®6 AND 8 TELESCOPES
UNPACKING
The Star Hopper®6 and 8 telescopes come in two boxes.
The first box contains the telescope tube, collimating tool, 25mm SMA 1¼" ocular, and the primary mirror, with
the pinnacle mirror cell.
The second box contains the parts necessary to assemble the altazimuth mount, including:
•Two side panels
•Front panel
•Base plate (with the four pre-drilled holes)
•Ground plate (with the teflon pads)
•Nylon sleeve
•Two washers
•Azimuth Pivot Bolt
•Azimuth Pivot Washer
•Wood screws
•Three rubber feet
•Plastic screw head caps
ASSEMBLY
Assembling the Mount for the Star Hopper®6 and 8
1. Locate the front panel and the two side panels of the base (refer to Figure 1 to identify all the parts referred to
in these instructions).
2. Align the predrilled holes of the side panels with the holes on the edge of the front panel and attach using four
of the wood screws. Do not completely tighten the screws yet. ( The Star Hopper®logo should be facing the
outside of the base).
3. Turn the side panel assembly upside down on a flat surface and align the predrilled hole on the base plate with
the holes on the bottom of the side panels.
4. Use the remaining wood screws to fasten the base plate to the side panels by inserting the screws through the
holes and tightening until the head of the screw is below the surface of the base plate.
5. Press on the black plastic caps over the heads of the wood screws.
6. Use a hammer to tap the rubber feet into the bottom of the ground plate. Position the feet so they are 120º
apart.
7. Place the base plate with side panels attached on top of the ground plate (so that the teflon pads are between
the two plates) and align the center holes.
8. Insert the nylon sleeve into the center hole of the base plate until it is flush with the top surface.

8
9. Place a Azimuth Pivot Washer over the center hole of the base plate (with the curved side facing down), and
insert the Azimuth Pivot Bolt through the top of the base plate and the nylon sleeve.
Figure 1
10. Thread the Azimuth Pivot Bolt into the T-nut at the bottom of the ground plate and tighten. (Note: If the
center bolt is over-tightened it will make the base difficult to rotate in azimuth).

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Assembling the Optical Tube
The optical tube assembly consists of eight parts, all of which are pre-assembled, except for the primary mirror. The
parts are as follow:
•Optical tube
•Focuser - .96" and 11/4"
•Secondary mirror assembly
•Two dovetail brackets
•Two altitude bearings
•V-Spectrum LTM optical system (primary mirror and cell)
Mounting the Primary Mirror
The primary mirror is mounted on the pinnacle mirror cell at Celestron. The pinnacle mirror cell fits into the rear of
the telescope tube and is secured with the three supplied mounting screws. To mount the mirror/cell into the back of
the tube:
1. Place the telescope tube on its side.
2. Locate the three holes, which are 120º apart, in the rear of the tube (i.e. the end opposite the focuser).
3. Remove tissue paper from the reflective surface of the mirror.
4. Place the mirror/cell assembly into the rear of the tube, mirror end first.
5. Orient the mirror cell such that the holes on the side of the cell best line up with the holes in the tube. (It may be
helpful to rotate the mirror cell 120°in either direction to find the best alignment of the holes).
6. Place a screw through the washer and tube and into the mirror cell. Only thread the first two screws into the
mirror cell about two turns allowing enough play to align the third screw.
7. Manually line up the last mirror cell hole with the tube hole and thread the screw into the mirror cell. Don’t
tighten completely until all three screws are threaded into the mirror cell. Tighten screws sequentially, for
balance.
Once the mirror is placed into the tube, it does not need to be removed again. The next thing to do is collimate, or
align the optics of the telescope. See the collimation section, on pages 12 and 14.
Mounting the Primary Mirror (Aluminum tube only)
1. Place the telescope tube on its side.
2. Locate the three holes, which are 120º apart, in the rear of the tube (i.e. the end opposite the focuser).
3. Remove tissue paper from the reflective surface of the mirror.

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4. Place a screw through the washer and inside one of
the tube holes.
5. From the inside of the tube, place a second washer
onto the screw and thread one of the hex head nuts
half way onto the screw (See Figure 6).
6. Thread the screw into the mirror cell hole. Only
thread the first two screws into the mirror cell about
two turns allowing enough play to align the third
screw.
7. Manually line up the last mirror cell hole with the
tube hole and thread the screw into the mirror cell.
Don’t tighten completely until all three screws are
threaded into the mirror cell. Tighten screws
sequentially, for balance.
8. After all three screws are in place, tighen the hex nut against the inner wall of the tube locking the mirror cell in
place (See Figure 7).
Balancing the Telescope
The Celestron Star Hopper®6 and 8 come with dovetail slide bars for balancing. This feature allows virtually any
optional accessory to be used with the telescopes, while still achieving balance easily. To balance the telescope:
Figure 6 -- Aluminum tube only
Figure 7 -- Rear view of aluminum tube model

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•Put the telescope tube in the rocker box.
•Orient the telescope tube so it is horizontal.
•With the telescope in the horizontal position, loosen the altitude hubs on both sides of the telescope.
•Slide the telescope in whichever direction it needs to go in order to achieve balance. If the telescope rotates such
that the front of the tube goes up, then slide the telescope forward and try again. If the rear goes up, then slide
the telescope toward the rear.
•Once a balanced position has been found, make sure the sides of the telescope tube are parallel to the sides of the
rocker box by moving the telescope tube slightly left or right within the rocker box, as needed.
•Tighten the altitude hubs.
Balancing the Star Hopper®4½
•Place the standard eyepiece in the focuser (or any optional eyepiece you choose).
•Place the telescope tube in the horizontal position.
•Loosen the clamp release screw on the tube ring. This allows the telescope tube to slide back and forth in the
ring.
•Slide the telescope, forward or backward, in the tube ring until the telescope is balanced.
•Tighten the clamp release screw on the tube ring.
Adjusting the friction on the Star Hopper®4½altitude axis
To accommodate individual preferences, the clutch tension is adjustable, but after a desired clutch tension is set, there
is no need to adjust it again. When properly adjusted, clutch tension should be light enough that the telescope can
move smoothly and easily, but tight enough that the wind won’t move the telescope.
To adjust the clutch tension:
•Balance the telescope and orient the tube in a horizontal position (see section above on balancing the telescope).
•Using the diagram on page 4, locate the altitude clutch adjustment screw. It is the bolt attaching the telescope
mounting ring to the mount.
•Use a wrench to tighten or loosen the bolt until the desired clutch tension is achieved.
•IMPORTANT: Don’t over tighten the bolt, as this could result in cracking the wood of the mount.
•A plastic screw is provided to give increased friction when viewing either with the telescope tube pointed straight
up, or in high wind conditions. This screw should make contact with the rotation disk (inside the side panel)
that the telescope is attached to without pressing hard against it, which would hinder altitude movement. NOTE:
When viewing objects near the zenith (straight up in the sky) the finderscope should be pointed either toward the
side panel or at a 180°angle away from it, for optimal balance.
Installing Finderscopes
(Optional Accessory)
Celestron offers optional finderscopes that are useful in pointing the telescope at a particular object and locating it in
your field of view. A finderscope is a small auxiliary telescope with cross hairs, of low power, but with a wide field
of view, and is attached to the main telescope. The Star Hopper®4½comes with a 5x24 finderscope. The Star
Hopper® 6and 8telescopes have a set of pre-drilled holes for the 6x30 finderscope, (item #93777) or the 5x24
finderscope (#93775). To install the finderscope, locate the two holes next to the focuser on the telescope tube. Place
the finderscope bracket on the telescope tube and line up the holes in the base of the bracket with the holes in the
tube. Use the screws and nuts provided with the finderscope to attach the bracket to the telescope tube. Do this by
putting the screws through the finderscope bracket and into the pre-drilled holes in the telescope tube, then
tightening them.
Besides the 6x30 or 5x24, another excellent finderscope option for the Star Hopper®6 and 8 is Celestron’s Star
Pointer (item #51630). For more options, see the Optional Accessories section on pages 23 and 24.

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Collimation
The optical performance of most Newtonian reflecting telescopes can be optimized by re-collimating (aligning) the
telescope's optics, as needed. To collimate the telescope simply means to bring its optical elements into balance.
Poor collimation will result in optical aberrations and distortions.
Before collimating your telescope, take time to familiarize yourself with all its components, using the diagrams on
pages 4 and 5. The primary mirror is the large mirror at the back end of the telescope tube. This mirror is adjusted
by loosening and tightening the three screws, placed 120 degrees apart, at the end of the telescope tube. The
secondary mirror (the small, elliptical mirror under the focuser, in the front of the tube) also has three adjustment
screws. To see what is necessary to go through the following steps, point your telescope toward a bright wall or blue
sky outside (see warning on page 3 regarding safe solar viewing). Once you have collimated your telescope, refer to
the chart on page 15 to confirm that your alignment is correct.
Do not touch the socket head cap screw in the center of the mirror cell of the Star Hopper®6 and 8.
Aligning the Secondary Mirror
If you have an eyepiece in the focuser, remove it. Pull the focuser tube in completely, using the focusing knobs, until
its silver tube is no longer visible. You will be looking through the focuser at a reflection of the secondary mirror,
projected from the primary mirror. During this step, ignore the silhouetted reflection from the primary mirror.
Insert the collimating cap into the focuser and look through it. With the focus pulled in all the way, you should be
able to see the entire primary mirror reflected in the secondary mirror. If the primary mirror is not centered in the
secondary mirror, adjust the secondary mirror screws by alternately tightening and loosening them until the periphery
of the primary mirror is centered in your view. DO NOT loosen or tighten the center screw in the secondary mirror
support, because it maintains proper mirror position.
Aligning the Primary Mirror
Now adjust the primary mirror screws to re-center the reflection of the small secondary mirror, so it’s silhouetted
against the view of the primary. As you look into the focuser, silhouettes of the mirrors should look concentric.
Repeat steps one and two until you have achieved this.
Remove the collimating cap and look into the focuser, where you should see the reflection of your eye in the
secondary mirror.
Night Time Star Collimating
After successfully completing daytime collimation, night time star collimation can be done by closely adjusting the
primary mirror while the telescope tube is on its mount and pointing at a bright star. The telescope should be set up
at night and a star's image should be studied at medium to high power (30-60 power per inch of aperture). If a non-
symmetrical focus pattern is present, then it may be possible to correct this by re-collimating only the primary mirror.
Procedure
(Please read this section completely before beginning)
To star collimate in the Northern Hemisphere, point at a stationary star like the North Star (Polaris). It can be found
in the north sky, at a distance above the horizon equal to your latitude. It’s also the end star in the handle of the Little
Dipper. Polaris is not the brightest star in the sky and may even appear dim, depending upon your sky conditions.

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Prior to re-collimating the primary mirror, locate the collimation screws on the end plate at the base of the telescope
tube. These three screws are to be adjusted one at a time. Normally, motions on the order of an 1/8turn will make a
difference, with approximately a 1/2 to 3/4 turn being the maximum required.
With Polaris or a bright star centered within the field of view, focus with either the standard ocular or your highest
power ocular, i.e. the shortest focal length in mm, such as a 6mm or 4mm. Another option is to use a longer focal
length ocular with a Barlow lens. When a star is in focus it should look like a sharp pinpoint of light. If, when
focusing on the star, it is irregular in shape or appears to have a flare of light at its edge, this means your mirrors
aren’t in alignment. If you notice the appearance of a flare of light from the star that remains stable in location, just
as you go in and out of exact focus, then re-collimation will help sharpen the image.
Take note of the direction the light appears to flare. For example, if it appears to flare toward the three o'clock
position in the field of view, then you must move whichever screw or combination of collimation screws necessary to
move the star’s image toward the direction of the flaring. In this example, you would want to move the image of the
star in your eyepiece, by adjusting the collimation screws, toward the three o'clock position in the field of view. It
may only be necessary to adjust a screw enough to move the star’s image from the center of the field of view to about
halfway, or less, toward the field's edge (when using a high power ocular).
Collimation adjustments are best made while viewing the star's position in the field of view and turning the
adjustment screws simultaneously. This way, you can see exactly which way the movement occurs. It may be helpful
to have two people working together: one viewing and instructing which screws to turn and by how much, and the
other performing the adjustments.
IMPORTANT: After making the first, or each adjustment, it is necessary to re-aim the telescope tube to re-center the
star again in the center of the field of view. The star image can then be judged for symmetry by going just inside and
outside of exact focus and noting the star's pattern. Improvement should be seen if the proper adjustments are made.
Since three screws are present, it may be necessary to move at least two of them to achieve the necessary mirror
movement.
ANSWERS TO FREQUENTLY ASKED QUESTIONS
Q. If I re-collimate the primary mirror, will alignment remain as I set it?
A. Yes, unless or until the telescope is severely jarred or bumped.
Q. Is exact collimation necessary?
A. For the majority of users, the collimation of the telescope, as delivered, will be satisfactory. Probably only those
requiring extremely sharp imagery will want or need to perform collimation, and then only once.
Q. Why is it necessary to re-center the star after each mirror adjustment?
A. All Newtonian telescopes have what is called off-axis coma (see glossary). Due to this, the best images are always
obtained in the center of an eyepiece view. Therefore, that is where you should judge star symmetry.
Q. On some nights the star's image fluctuates in size, position and symmetry without my doing anything. What is
the cause of this?
A. This represents turbulent “seeing,” which is caused by several factors (please see pages 18 and 19 for a full
description). Some steps you can take to minimize visual disturbances are to let the telescope tube remain outside for
30 minutes before judging symmetry, allowing time for the temperature within the telescope tube to balance with that
of the outer environment. It will also help to wait for a still night or a still time of night. Further, be aware that
using your telescope near a heat source such as a rooftop, car hood or any surface retaining daytime heat on a cool
night will cause local thermal turbulence and must be avoided.
Q. What if the daytime adjustment appears off after star collimating the primary mirror at night?
A. If star images look great, that is the bottom line. No further adjustment is necessary.

14
Newtonian collimation views as seen through the focuser using the collimation cap.
Figure A: With the collimation cap in, if you cannot see the entire primary
mirror reflected in the secondary mirror, the secondary mirror will need
adjustment. To do this, adjust the secondary collimation screws by alternately
tightening and loosening them until the outer edge of the primary mirror is
reflected in the secondary mirror and the dark ring of the collimation tool is
centered in the secondary mirror.
Figure B: Now that
you can see the entire primary mirror reflected in the
secondary mirror, you will notice that the secondary mirror
is not perfectly centered in the primary mirror. To correct
this, you must adjust the primary collimation screws located
at the bottom of the primary mirror cell (see figure 3).
Figure C: With both mirrors aligned you should see the silhouette of the
secondary mirror positioned in the center of the primary mirror.
Figure D: After removing the
collimation cap, you should see your eye reflecting back at you from the
center of both mirrors. Collimation is now completed.

15
TELESCOPE BASICS
Focusing the Telescope
To focus your telescope, begin by putting the eyepiece in the eyepiece holder of the focuser. When doing
astronomical viewing, you’ll find that out of focus star images are very diffuse and difficult to see. Therefore, choose
a bright object, like the moon or a planet for your first astronomical target. This way, the image will be visible even
when out of focus. Turn the focus knob until the object’s image becomes sharp. If you’re focusing on a star, its
image should, as closely as possible, resemble a pinpoint. If you’re focusing on the moon or a planet, turn the focus
knob until the image is sharp.
Pointing the Telescope
To aim your telescope, first locate a bright star near the object you are trying to find. You can then use your telescope
tube to sight with, helping to zero in on the object you wish to view. This can be done much as you might sight down
the barrel of a gun when lining up a shot. The idea is to use the line of the telescope tube to assist you in creating a
visual line between your eye and the object you want to view. Once the star is aligned with the edge of the telescope
tube, look inside the eyepiece and gently move the tube up and down and from side to side until you see the object in
the field of view. Use of an optional finderscope makes locating objects for viewing much easier.
Calculating Magnification
You can change the viewing power of your Celestron Star Hopper®telescope just by changing the eyepiece
(ocular). There are various optional eyepieces shown in the Optional Accessories section of this manual on pages 24
and 25. To determine the magnification of your telescope, simply divide the focal length of the telescope by the focal
length of the eyepiece used. In equation format, the formula looks like this:
Focal Length of Telescope (mm)
Magnification = ––––––
Focal Length of Eyepiece (mm)
To determine the magnification using the standard 25mm eyepiece, simply divide the focal length of your 6” or 8”
Star Hopper®telescope (1220mm) by the focal length of the eyepiece (25mm). Dividing 1220mm by 25 yields a
magnification of 49 power. Although the power is variable, each telescope, used under average skies, has a limit to
its highest useful magnification. The general rule is that 60 power is the maximum that can be used for every inch of
aperture, although seeing condition rarely allow this. For example, the Star Hopper®8 is 8" in diameter.
Multiplying 8 by 60 gives a maximum useful magnification of 480 power. Although this is the maximum useful
magnification, most observing is done in the range of 20 to 35 power for every inch of aperture, which is 90 to 158
for the Star Hopper®4½, 120 to 210 for the Star Hopper®6 and 160 to 280 times for the Star Hopper®8.
Determining Field of View
Determining the field of view is important if you want to get an idea of the angular size of the object you are
observing. To calculate the actual field of view, divide the apparent field of the eyepiece (supplied by the eyepiece
manufacturer) by the magnification. In equation format, the formula looks like this:
Apparent Field of Eyepiece
True Field = 
Magnification

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As you can see, before determining the field of view, you must calculate the magnification. Using the example above,
we can determine the field of view using the same 25mm eyepiece. The 25mm SMA eyepiece has an apparent field
of view of 52°. Divide the 52° by the magnification, which is 49 power. This yields an actual field of 1.06°, or a
little over a degree. The apparent field of each eyepiece that Celestron manufactures is found in the Celestron
Accessory Catalog (#93685).
CELESTIAL OBSERVING
Now that your telescope is set up, you’re ready to use it for observing. This section covers visual observing for both
solar system and deep-sky objects.
Observing the Moon
In the night sky, the moon is a prime target for your first look because it is extremely bright and easy to find.
Although the beauty of the full moon may make it seem a perfect viewing object, in fact, the light reflected from its
fully illuminated face can be overpowering. In addition, little or no contrast can be seen during this phase.
One of the best times to observe the moon is during its partial phases, such as a crescent or quarter moon. At these
times, long shadows reveal a great amount of detail on the lunar surface. At low power, with the standard eyepiece,
you’ll be able to see the whole lunar disk at one time. Change to higher power (magnification) with an optional
eyepiece to focus in on a smaller area. Keep in mind that the rotation of the earth will cause the moon to drift out of
your field of view. You’ll have to manually adjust the telescope to keep the moon centered. This effect is more
noticeable at higher power. Consult a current astronomy magazine or your local newspaper to find out the current
phase of the moon.
Lunar Observing Hint
To increase contrast and bring out visible detail on the lunar surface, try using different filters (available through
your local Celestron dealer). A yellow filter works well for improving contrast.
Observing the Planets
Other easy targets include the five “naked eye” planets of our solar system, so called because they can be spotted in
the night sky by the unaided eye. You can see Venus go through its lunar-like phases. Mars can reveal a host of
surface detail and one, if not both, of its polar caps. You’ll be able to see the cloud belts of Jupiter, perhaps even the
great Red Spot. In addition, you’ll be able to see the moons of Jupiter as they orbit the giant planet. Saturn, with its
beautiful rings, is easily visible at moderate power, as is Mercury. All you need to know is where to look. Most
astronomy publications indicate where the planets are in the sky each month.
This drawing of Jupiter provides a good representation of what you can expect to see with moderate
magnification, during good “seeing” conditions.

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Observing the Sun
Although overlooked by many amateur astronomers, solar observation is both rewarding and fun. However, because
the sun is so bright, special precautions must be taken when observing this star, so as not to damage your eyes or your
telescope. Never project an image of the sun through the telescope. This can damage the telescope and/or any
accessories attached to the telescope. For safe solar viewing, use a Celestron solar filter (available for the Star
Hopper®4½and 8). The filter reduces the intensity of the sun's light, making it safe to view. With this filter you
can see sunspots as they move across the solar disk and faculae, which are bright patches seen near the sun's edge. If
you purchased an optional finderscope, be sure to cover its lens or remove it completely when observing the sun.
This will ensure that the finderscope itself is not damaged and that no one looks through it inadvertently.
Solar Observing Hints
•The best time to observe the sun is in the early morning or late afternoon, when the air is cooler.
•To locate the sun without a finderscope, watch the shadow of the telescope tube until it forms a circular shadow.
Observing Deep-Sky Objects
Deep-skyobjects are simply those objects outside the boundaries of our solar system. They include star clusters,
planetary nebulae, diffuse nebulae, double stars and other galaxies outside our own Milky Way. Unlike the sun,
moon and our five major planets, most deep-sky objects are not visible to the naked eye. Finding them requires a
method called star hopping, described below. Celestron Sky Maps (#93722) can help you locate the brightest deep-
sky objects.
Most deep-sky objects have a large angular size. Therefore, a low-to-moderate power lens is all you need to see them.
Visually, they are too faint to reveal any of the color seen in long exposure photographs. Instead, they appear black
and white. Because of their low surface brightness, they should be observed from a “dark-sky” location. Light
pollution around large urban areas washes out most nebulae making them difficult, if not impossible, to observe.
Star Hopping
One way to find deep-sky objects is by star hopping and a finderscope is very helpful. Star hopping is done by using
bright stars to "guide" you to an object. For successful star hopping, it is helpful to know the field of view of you
telescope. If you’re using the standard Celestron 25mm SMA ocular, your field of view is more than 1º. If you
know an object is 3º away from your present location, than you just need to move 3 fields of view. If you’re using
another ocular, then consult the section on determining field of view on page 16. Listed below are directions for
locating two popular objects.
The Andromeda Galaxy, also known as M31, is an easytarget. To find M31:
1. Locate the constellation of Pegasus, a large square visible in the fall (in the eastern sky, moving toward the point
overhead) and winter months (overhead, moving toward the west).
2. Start at the star in the northeast corner—Alpha (α) Andromedae.
3. Move northeast approximately 7°. There you will find two stars of equal brightness—Delta (δ) and Pi (π)
Andromeda—about 3° apart.
4. Continue in the same direction another 8°. There you will find two stars—Beta (β) and Mu (µ) Andromedae—
also about 3° apart.
5. Move 3° northwest—the same distance between the two stars—to the Andromeda galaxy.

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Star hopping to the Andromeda Galaxy (M31) is a snap, since all the stars needed to do so are visible to the naked
eye.
Star hopping may take some getting used to since you can see more stars through a finderscope (optional with the 6”
and 8”) than you can see with the naked eye. Also, some objects are not visible in a finderscope. One such object is
M57, the famed Ring Nebula. Here's how to find it:
1. Find the constellation of Lyra, a small parallelogram visible in the summer and fall months. Lyra is easy to pick
out because it contains the bright star Vega.
2. Start at the star Vega—Alpha (α) Lyrae—and move a few degrees southeast to find the parallelogram. The four
stars that make up this geometric shape are all similar in brightness, making them easy to see.
3. Locate the two southernmost stars that make up the parallelogram—Beta (β) and Gamma (γ) Lyra.
4. Point the finderscope halfway between these two stars.
5. Move about ½° toward Beta (β) Lyra, while remaining on a line connecting the two stars.
6. Look through the telescope and the Ring Nebula should be in your field of view. The Ring Nebula’s angular size
is quite small and, therefore, not visible in the finderscope.
7. Because the Ring Nebula is rather faint, you may need to use “averted vision” to see it. “Averted vision” is a
technique of looking slightly away from the object you’re observing. So, if you are observing the Ring Nebula,
center it in your field of view and then look off toward the side. This causes light from the object viewed to fall
on the black and white sensitive rods of your eyes, rather than your eyes color sensitive cones. These two
examples should give you an idea of how to star hop to deep-sky objects. To use this method on other objects,
consult any of the star atlases, then star hop to the object of your choice using “naked eye” stars.

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Although the Ring Nebula lies between two “naked eye” stars, it may take a little time to locate because it isn’t
visible in a finderscope. Note that the scale for this star chart is different from that of the chart on the previous page,
which shows several constellations, including Pegasus, Triangulum and Andromeda.
“Seeing” Conditions
Viewing conditions affect what you can see through your telescope during an observing session. Conditions include
transparency, sky illumination and “seeing”. Understanding viewing conditions and the affect theyhave on
observing will help you get the most out of your telescope.
Transparency
Transparency refers to the clarity of the atmosphere and is affected by clouds, moisture, dust and other airborne
particles. Thick cumulus clouds are completely opaque, while cirrus clouds can be thin, allowing light from the
brightest stars through. Hazy skies absorb more light than clear skies, making fainter objects hard to see and
reducing contrast on brighter objects. Dust particles and gases ejected into the upper atmosphere from volcanic
eruptions also affect transparency. Ideal conditions are when the night sky is inky black.
Sky Illumination
General sky brightening caused by the moon, aurorae, natural airglow and light pollution greatly effect transparency.
While not a problem when viewing brighter stars and planets, bright skies reduce the contrast of extended nebulae,
making them difficult, if not impossible, to see. To maximize your observing, limit deep-sky viewing to moonless
nights, far from the light polluted skies found around major urban areas. Light Pollution Reduction (LPR) filters
enhance deep-sky viewing from light polluted areas by blocking unwanted light, while transmitting light from certain
deep-sky objects. Planets and stars can still be observed from light polluted areas or when the moon is out.