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SUN HAZARD
— Never look directly at the sun
with this device.
WARNING:
CHOKING HAZARD
— Small parts.
Not for children under 3 years.
WARNING:
The lens contains lead that may be harmful.
Wash hands after touching.
WARNING:
This product can expose you to chemicals including lead,
which is known to the State of California to cause cancer.
For more information go to www.P65Warnings.ca.gov.
WARNING:
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INSTRUCTION MANUAL
75 MM COMPACT
REFLECTOR TELESCOPE
80-20103
EN
10+
2
Customer Service: Call 1-866-252-3811
• SUN WARNING:
WARNING: NEVER ATTEMPT TO OBSERVE THE SUN WITH THIS DEVICE! OBSERVING THE
SUN EVEN FOR A MOMENT WILL CAUSE INSTANT AND IRREVERSIBLE DAMAGE TO YOUR EYE OR EVEN
BLINDNESS. EYE DAMAGE IS OFTEN PAINLESS, SO THERE IS NO WARNING TO THE OBSERVER THAT THE
DAMAGE HAS OCCURRED UNTIL IT IS TOO LATE. DO NOT POINT THE DEVICE AT OR NEAR THE SUN. DO NOT
LOOK THROUGH THE DEVICE AS IT IS MOVING. CHILDREN SHOULD ALWAYS HAVE ADULT SUPERVISION WHILE
OBSERVING.
• RESPECT PRIVACY: WHEN USING THIS DEVICE, RESPECT THE PRIVACY OF OTHER PEOPLE. FOR EXAMPLE, DO NOT
USE IT TO LOOK INTO PEOPLE’S HOMES.
• CHOKING HAZARD: CHILDREN SHOULD ONLY USE DEVICE UNDER ADULT SUPERVISION. KEEP PACKAGING
MATERIALS LIKE PLASTIC BAGS AND RUBBER BANDS OUT OF THE REACH OF CHILDREN AS THESE
MATERIALS POSE A CHOKING HAZARD.
• RISK OF BLINDNESS: NEVER USE THIS DEVICE TO LOOK DIRECTLY AT THE SUN OR IN THE DIRECT PROXIMITY OF THE
SUN. DOING SO MAY RESULT IN A PERMANENT LOSS OF VISION.
• RISK OF FIRE: DO NOT PLACE DEVICE, PARTICULARLY THE LENSES, IN DIRECT SUNLIGHT. THE CONCENTRATION OF
LIGHT RAYS COULD CAUSE A FIRE.
• DO NOT DISASSEMBLE THIS DEVICE: IN THE EVENT OF A DEFECT, PLEASE CONTACT YOUR DEALER. THE DEALER
WILL CONTACT THE CUSTOMER SERVICE DEPARTMENT AND CAN SEND THE DEVICE IN TO BE REPAIRED IF
NECESSARY.
• DO NOT SUBJECT THE DEVICE TO TEMPERATURES EXCEEDING 60 °C 140 °F.
• DISPOSAL: KEEP PACKAGING MATERIALS, LIKE PLASTIC BAGS AND RUBBER BANDS, AWAY FROM
CHILDREN AS THEY POSE A RISK OF SUFFOCATION. DISPOSE OF PACKAGING MATERIALS AS LEGALLY
REQUIRED. CONSULT THE LOCAL AUTHORITY ON THE MATTER IF NECESSARY AND RECYCLE MATERIALS
WHEN POSSIBLE.
• THE WEEE SYMBOL IF PRESENT INDICATES THAT THIS ITEM CONTAINS ELECTRICAL OR ELECTRONIC
COMPONENTS WHICH MUST BE COLLECTED AND DISPOSED OF SEPARATELY.
• NEVER DISPOSE OF ELECTRICAL OR ELECTRONIC WASTE IN GENERAL MUNICIPAL WASTE. COLLECT AND
DISPOSE OF SUCH WASTE SEPARATELY.
• MAKE USE OF THE RETURN AND COLLECTION SYSTEMS AVAILABLE TO YOU, OR YOUR LOCAL RECYCLING PROGRAM.
CONTACT YOUR LOCAL AUTHORITY OR PLACE OF PURCHASE TO FIND OUT WHAT SCHEMES ARE AVAILABLE.
• ELECTRICAL AND ELECTRONIC EQUIPMENT CONTAINS HAZARDOUS SUBSTANCES WHICH, WHEN DISPOSED OF
INCORRECTLY, MAY LEAK INTO THE GROUND. THIS CAN CONTRIBUTE TO SOIL AND WATER POLLUTION WHICH IS
HAZARDOUS TO HUMAN HEALTH, AND ENDANGER WILDLIFE.
• IT IS ESSENTIAL THAT CONSUMERS LOOK TO RE-USE OR RECYCLE ELECTRICAL OR ELECTRONIC WASTE TO AVOID IT
GOING TO LANDFILL SITES OR INCINERATION WITHOUT TREATMENT.
BUTTON/COIN BATTERY WARNING: THIS PRODUCT CONTAINS A BUTTON OR COIN CELL BATTERY. A SWALLOWED
BUTTON OR COIN CELL BATTERY CAN CAUSE INTERNAL CHEMICAL BURNS IN AS LITTLE AS TWO HOURS AND LEAD
TO DEATH. DISPOSE OF USED BATTERIES IMMEDIATELY. KEEP NEW AND USED BATTERIES AWAY FROM CHILDREN. IF
YOU THINK BATTERIES MIGHT HAVE BEEN SWALLOWED OR PLACED INSIDE ANY PART OF THE BODY, SEEK IMMEDIATE
MEDICAL ATTENTION.
IMPORTANT SAFETY INSTRUCTIONS
READ AND FOLLOW THE INSTRUCTIONS BEFORE USE.
KEEP THESE INSTRUCTIONS FOR LATER USE.
3
What’s Included:
Parts Overview
1. Focus Wheel
2. Telescope (Optical Tube Assembly)
3. Compass
4. Alt-azimuth Mount
5. Azimuth Scale
6. Scale with 90 Scale
7. Height Adjustment Wheel
8. 6 mm and 20 mm Eyepieces
9. 2x Barlow Lens
10. Moon filter
Available Downloads Visit:
www.esmanuals.com
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1
2
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Using Your Telescope:
Note: We recommend assembling your telescope for the first time in the daylight or in a lit room so
that you can familiarize yourself with assembly steps and all components.
Please look for a suitable location to set up your telescope before you begin. Use a stable surface like
a table or counter top.
Azimuthal mounting means that you can move your telescope up and down, left and right. With the
height adjustment wheel (7) and the rotatable azimuth mount, you can point the telescope at any
object you want. Use the wheel (7) to tilt the telescope up and down. By using the azimuth mount like a
turntable you can pan the telescope to the left and to the right.
It is important that you always choose an eyepiece with the highest focal width for the beginning of your
observation. Afterwards, you can gradually move to eyepieces with smaller focal widths. The focal width
is indicated in millimeters, and it is written on each eyepiece. In general, the larger the focal width of an
eyepiece, the smaller the magnification. There is a simple formula for calculating the magnification:
Focal width of the telescope tube / Focal width of the eyepiece = Magnification
The magnification also depends on the focal width of the telescope tube. The telescope has a focal
length of 350 mm. From this formula, we see that if you use an eyepiece with a focal width of 20 mm, you
will get the following magnification:
350 mm / 20 mm = 18x magnification
Cleaning:
Your telescope is a precision optical device and keeping the optics free of dust and dirt is crucial for
optimal performance. To clean the lenses (objective and eyepiece) use only a photo-grade soft brush or
a lint-free cloth, like a microfiber cloth. Do not press down too hard while cleaning, as this might scratch
the lens. If necessary, the cleaning cloth can be moistened with an optical glass cleaning fluid and the lens
wiped clean using very little pressure. The eyepiece is NOT waterproof so do not spray fluids directly
onto the glass or dip it in water. Never use harsh detergents! After you have finished cleaning an
eyepiece, allow it to fully dry before storing.
Make sure your telescope is always protected against dust and dirt. After use, leave it in a warm room to
dry off before storing.
Focal Length Eyepiece Magnification 2x Barlow Lens
350 mm 20 mm 18x 35x
350 mm 6 mm 58x 117x
5
Troubleshooting Guide:
Problem Solution
No picture Remove dust protection cap (if included).
Blurred picture Adjust focus using focus wheel.
No focus possible Wait for temperature to balance out.
Bad quality Never observe through a glass surface such as a window.
6
Observing Tips:
Star hopping
Star hopping is a technique used by amateur astronomers to navigate the night sky. By using easily
recognizable constellations and asterisms as a guide, an observer can locate stars and other objects.
For example, Polaris, which is
commonly referred to as The
North Star, can be located quickly
using star hopping. First, find the
Big Dipper asterism in the Ursa
Major constellation. The popular
pattern is defined by seven stars,
and the two stars on the front
edge of the Big Dipper’s “bowl”
are Merak and Dubhe. Next, draw
an imaginary line from the bottom
star (Merak) on this front edge
through the top star (Dubhe) on
the front edge. Follow the line to
the first bright star you see. That
should be Polaris. Finally, to verify
your finding, locate the Little
Dipper asterism. Polaris is the
anchor star at the end of the Little Dipper’s “handle.”
BIG DIPPER
LITTLE DIPPER
POLAR STAR
CASSIOPEIA
Caph
Zeta
Beta
Kochab
Pherkad
Gamma
Eta
Epsilon
Delta
Alpha
Shedar
Cih
Ksora
Segin
Alkaid
Alcor
Mizar
Alioth
Megrez
Phecda
Merak
Dubhe
Orion Nebula(M42):
Right ascension: 05: 35.4 (hours: minutes)
Declination: -05: 27 (degrees: minutes)
Distance: Approximately 1,344 light years
The Orion Nebula is a vast star-forming region located in the
“sword” branching off of the famous Orion’s Belt. Also known
as Messier 42, this diffuse nebula is bright enough to see with
the unaided eye — although it will only appear as a slightly
foggy star. However, with your telescope, you can see many of
the beautiful details, such as the billowing clouds of gas and
dust where new stars are being born.
Image credit: NASA, ESA, M. Robberto (Space Telescope Science Institute/ESA)
and the Hubble Space Telescope Orion Treasury Project Team
Image credit: Howard Eskildsen
Note: Images are for illustration purposes only. Quality of your image may very depending upon atmospheric conditions and location.
Possible Objects for Observation:
What you can observe at any one time in your telescope depends
on several factors beyond aperture and magnification. These
factors include location, date, time and sky conditions. The
following are all objects that can be seen with the unaided eye
and/or binoculars. Your telescope can enhance views of any of
these objects if the observing conditions are right.
The Moon:
Diameter: 3,476 km
Distance: Approximately 384,401 km
The Moon is the Earth’s only natural satellite, and it is the second
brightest object in the sky (after the Sun). Although it is our
closest neighbor, a lot of people have never really taken a good
long like at the Moon. With your telescope, you should be able to
see several interesting lunar features. These include lunar maria,
which appear as vast plains, and some of the larger craters. The
best views will be found along the terminator, which is the edge
where the visible and shadowed portions of the Moon meet.
Note: The positioning of the Big Dipper in relation to the Little
Dipper does not change, but the orientation of both in the night sky
will rotate throughout the year due to the motion of the Earth.
77
Pleiades Star Cluster(M45):
Right ascension: 03: 47.0 (hours: minutes)
Declination: +24: 07 (degrees: minutes)
Distance: Approximately 444 light years
The Pleiades Star Cluster is a group of brilliant blue
stars located in the Taurus Constellation. Also known
as Messier 45 or “Seven Sisters”, this open star cluster
consists of more than 1,000 confirmed stars, although
an average of only six are visible to the unaided eye.
With your telescope, you can quickly reveal some
of the more elusive members of this legendary and
beautiful cluster.
Dumbbell Nebula(M27)
Right ascension: 19:59.6 (hours: minutes)
Declination: +22:43 (degrees: minutes)
Distance: Approximately 1,360 light years
The Dumbbell Nebula was the first planetary nebula
ever discovered. It is one of the most popular sights
in the Vulpecula constellation. Easy to find with
binoculars and amazing in a telescope, the shape of
this bright, double-lobed nebula has been compared
to a dumbbell, an hourglass or an apple core. As an
added bonus, the white dwarf that lies at the heart of
the Dumbbell Nebula is larger than any other star of
its kind.
Andromeda Galaxy(M31):
Right ascension: 00: 42.7 (hours: minutes)
Declination: +41: 16 (degrees: minutes)
Distance: Approximately 2.54 million light years
The Andromeda Galaxy is the closest major galaxy
to our own Milky Way. Also known as Messier 31, this
famous spiral galaxy is part of the Local Group of
galaxies. Although it is technically bright enough to
see with the unaided eye under a very dark sky, your
telescope may show its bright center, hints of its spiral
structure and its much smaller companion galaxies
known as M32 and M110.
Image credit: NASA/JPL-Caltech/UCLA
Image credit: NASA/JPL-Caltech/Harvard-Smithsonian CfA
Image credit: NASA/JPL-Caltech
Note: Images are for illustration purposes only. Quality of your image may very depending upon atmospheric conditions and location.
88
Light
Light
Secondary Mirror
Primary Mirror
(Objective)
Focuser
Focuser
Light
Light
Objective Lens
Light
Light
Secondary Mirror
Primary Mirror (Objective)
Correcting Lens
Reflector
(Newtonian)
Refractor
Catadioptric
(Maksutov-Cassegrain/
Schmidt-Cassegrain)
Light
Light
Secondary Mirror
Primary Mirror
(Objective)
Focuser
Focuser
Light
Light
Objective Lens
Light
Light
Secondary Mirror
Primary Mirror (Objective)
Correcting Lens
Reflector
(Newtonian)
Refractor
Catadioptric
(Maksutov-Cassegrain/
Schmidt-Cassegrain)
Light
Light
Secondary Mirror
Primary Mirror
(Objective)
Focuser
Focuser
Light
Light
Objective Lens
Light
Light
Secondary Mirror
Primary Mirror (Objective)
Correcting Lens
Reflector
(Newtonian)
Refractor
Catadioptric
(Maksutov-Cassegrain/
Schmidt-Cassegrain)
Reflector
A reflector telescope uses mirrors to gather and focus light. Light enters the telescope through its open
front end and travels to the concave primary mirror at the back. From there the light is reflected back up
the tube to a flat secondary mirror, which sits at a 45° angle in relation to the eyepiece. Light bounces off
of this secondary mirror and out through the eyepiece. A reflector telescope is designed for astronomical
use. Terrestrial objects may appear inverted, sideways or at an angle depending on how your tube is
oriented due to optical design. This rotation is perfectly normal on all Newtonian reflectors and will not
affect astronomical viewing.
Refractor:
A refracting telescope uses a collection of lenses to gather and focus light. A refractor’s views will
be upside down if a diagonal is not in use. A standard diagonal will generate a “right side up” image,
however, it will rotate the image on the vertical axis (mirror image). To get the “right side up” image
without the rotation, you will need to use a special diagonal with an erect image prism.
Catadioptric:
A catadioptric telescope uses a combination of mirrors and lenses to gather and focus light. Popular
catadioptric designs include the Maksutov-Cassegrain and Schmidt-Cassegrain.
Types Of Telescopes:
99
Aperture:
This figure, which is usually expressed in millimeters, is the diameter of a telescope’s light-gathering
surface (objective lens in a refractor or primary mirror in a reflector). Aperture is the key factor in
determining the brightness and sharpness of the image.
Objective Lens:
The objective lens is the main light-gathering component of a refractor telescope. It is actually composed
of several lens elements.
Diagonal:
This accessory houses a mirror that deflects the ray of light 90 degrees. With a horizontal telescope tube,
this device deflects the light upwards so that you can comfortably observe by looking downwards into
the eyepiece. The image in a standard diagonal mirror appears upright, but rotated around its vertical
axis (mirror image). To get an image without this rotation, you will need to use a special diagonal with an
erect image prism.
Eyepiece:
An eyepiece is an optical accessory comprised of several lens elements. It determines the magnification
of a particular observing setup.
Primary Mirror:
The primary mirror is the principle light-gathering surface of a reflector telescope.
Secondary Mirror:
A secondary mirror is a small mirror that sits at a 45° angle in relation to the primary mirror of a reflecting
telescope. Light from the primary mirror is reflected back up the tube to the secondary mirror. The light is
directed from this mirror up into the eyepiece.
Objective Lens
Aperture
(mm)
Aperture
(mm)
Eyepiece
Diagonal Focal Point
Focal Point
Focal Length Telescope
(mm)
Focal Length Telescope
(mm)
Focal Length
Eyepiece
(mm)
Focal Length
Eyepiece
(mm)
Focuser
Secondary
Mirror
Primary Mirror
(Objective)
Focuser
Eyepiece
Telescope Terms to Know:
1010
Magnification:
The magnification corresponds to the difference between observation with the naked eye and
observation through a magnifying device like a telescope. If a telescope configuration has a magnification
of 30x, then an object viewed through the telescope will appear 30 times larger than it would with the
naked eye. To calculate the magnification of your telescope setup, divide the focal length of the telescope
tube by the focal length of the eyepiece. For example, a 20mm eyepiece in a telescope with a 1000mm
focal length will result in 50x power, which will make the object appear 50 times larger. If you change the
eyepiece, the power goes up or down accordingly.
Focal ratio
The focal ratio of a telescope is determined by dividing the telescope’s focal length by its aperture
(usually expressed in millimeters). It plays a key role in determining a telescope’s field of view and
significantly impacts imaging time in astrophotography. For example, a telescope with a focal length of
1000mm and a 100mm clear aperture has a focal ratio of f/10.
Focal length (Telescope):
The focal length is the distance in millimeters between the objective lens or primary mirror and the point
at which entering light rays converge — otherwise known as the focal point. The focal lengths of the
telescope tube and the eyepiece are used to determine magnification.
Focal length (Eyepiece):
The focal length is the distance in millimeters between the center of the first lens element in an eyepiece
and the focal point. The focal lengths of the telescope tube and the eyepiece are used to determine
magnification. Short eyepiece focal lengths produce higher magnifications than long eyepiece focal
lengths.
Exit Pupil
The exit pupil is the diameter of the beam of light coming out of the eyepiece. To calculate exit pupil,
divide the focal length of your eyepiece by your telescope’s focal ratio. For example, if you use a 20mm
eyepiece with an f/5 telescope, the exit pupil would be 4mm.
Magnification =
Telescope Focal Length
Eyepiece Focal Length
Focal Ratio =
Telescope Focal Length
Telescope Aperture
Exit Pupil =
Eyepiece Focal Length
Telescope Focal Ratio
Eyepiece Lens
Long Eye Relief Distance
Eyepiece Lens
Short Eye Relief Distance
Eyepiece Lens
Exit Pupil (mm)
Telescope Focal Length
1000mm
Eyepiece
Focal Length
20mm
Aperture
102mm
11
Eyepiece Lens
Long Eye Relief Distance
Eyepiece Lens
Short Eye Relief Distance
Eyepiece Lens
Exit Pupil (mm)
Eyepiece Lens
Long Eye Relief Distance
Eyepiece Lens
Short Eye Relief Distance
Eyepiece Lens
Exit Pupil (mm)
Eye Relief
Eye relief is all about a comfortable viewing experience because it is the distance at which you need to
position your eye from the eyepiece’s outermost surface to enjoy the full field of view. This characteristic
is of special concern to observers who wear glasses to correct an astigmatism, because a long enough
eye relief is necessary to allow room
for glasses.
Huygenian Eyepieces:
A Huygenian eyepiece uses two plano-convex lenses separated by an air gap. They have a fairly narrow
apparent field of view.
Kellner Eyepieces:
A Kellner eyepiece uses three lens elements - two of which are paired together in an achromatic doublet
design to minimize chromatic aberrations. They typically produce an apparent field of view around 45°.
Plössl Eyepieces:
A Plossl eyepiece uses two doublets (a pairing of lens) for a total of four lens elements. This eyepiece
design delivers sharp views and an apparent field of view of approximately 50°, which works well for both
planetary and deep sky viewing.
Barlow Lens:
A Barlow lens effectively increases the focal length of a telescope. It is inserted between the eyepiece
and the focuser/diagonal (depending on the optical setup) and multiplies the magnification power of the
eyepiece. For example, a 2x Barlow will double the magnification of a particular eyepiece.
Barlow Lens
2 Lens Elements
Huygenian Eyepiece
2 Lens Elements
Light
Kellner Eyepiece
3 Lens Elements
Light
Plössl Eyepiece
4 Lens Elements
Light
Light
Eye Lens
Field Lens
Eye Lens
Field Lens
Field Lens
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V012021
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