Explore Scientific AR152 Air-Spaced Doublet Owner Manual

By giving others a deeper understanding
of the universe, our products serve an
important purpose, and we want to help
you sustain them.
To activate your Explore STAR warranty,
simply register the product with Explore
Scientific within 60 days of purchase.
That is why we offer Explore STAR – our
fully transferrable, unlimited lifetime
warranty that covers any problem no
matter the cause and guarantees an unprecedented level of satisfaction that can
be passed on to future owners.
To complete your registration, select one
of the following options.
• Visit http://explorescientificusa.
com/pages/warranty and click on the
“Registration” tab.
To obtain this impressive coverage, all
you have to do is register your Explore
Scientific branded telescope within 60
days of purchase. We encourage you to
do so today, so your telescope can be
protected for a lifetime.
• Mail in the enclosed Registration Card
• Call our Customer Service Department
at 866.252.3811.
2
CONNECT.
DISCOVER.
We live in a world of distractions populated
by devices that foster detachment. But
there are other worlds filled with inspiring
landscapes, unimaginable beauty and the
primordial matter that unites us. With your
Explore Scientific telescope, your family
can visit these places together and connect
with each other through the cosmos.
Whether your interests lie in our lunar
neighbor, our planetary brethren or the
mysterious residents of deep sky, your
Explore Scientific telescope can reveal the
secrets you seek. Each night can present
new targets, new challenges and new
revelations. So turn your scope to the sky
and discover what wonders await.
CAPTURE.
SHARE.
For some, preserving the beauty unfolding
in their eyepieces is the ultimate goal. If
you want to take your explorations beyond
observation and into astrophotography, the
precision optics of your Explore Scientific
telescope can give you the contrast and
crispness you need to capture the night
sky’s treasures in stunning detail.
Watching people’s face light up when you
show them Saturn’s elegant rings or the
Moon’s chiseled terrain for the first time
is a rewarding experience. By taking your
Explore Scientific telescope out to a star
party, a street corner or any outreach
event, you can share your eyepiece and
awaken others to the marvels of the sky.
3
THANK YOU
We would like to thank you for selecting an Explore Scientific telescope as your pathway
to the stars.
Since 2008, Explore Scientific has been on a mission to make astronomy accessible and
provide a truly transformative experience by giving people the tools and guidance they
need to explore the skies.
With our high-end optics and well-executed design, our precision optical instruments
enhance your observing experience by rising to the highest standards of clarity, contrast
and functionality. We also aim to exceed your service expectations by providing our
exclusive Explore Star Forever Warranty that guarantees an unprecedented level of
satisfaction.
We think of our telescopes as more than products. They are gateways to the universe
that will broaden your perspective by revealing the intricate beauty of our nearest
neighbors as well as the bounty of celestial wonders that lie well beyond our humble
solar system.
The adventures this telescope can send you on are immeasurable, and we encourage
you to enjoy it fully, use it often and share with others. All of us at Explore Scientific
want you to have the experience you deserve, so please do not hesitate to contact our
Customer Service Center with your questions or suggestions through an online chat at
www.explorescientificusa.com or by calling (866) 252-3811.
Scott Roberts
Robert Price
President and Founder
Explore Scientific, LLC
Chief Sales Officer and Managing Partner
Explore Scientific, LLC
4
TABLE OF CONTENTS
Table of Contents
AR Doublet Series
6-8
9-11
ED Triplet Essential Series
Carbon Fiber Series
12-15
Eyepieces
16-18
Finder Scopes
19-21
Focusers
22-24
Share The Sky
25
5
AR DOUBLET SERIES
Welcome to our AR Doublet Series
Designed to deliver crystal clear imagery full of contrast, the telescopes in our AR
Doublet Series will reveal the universe’s breathtaking sights with rich detail. Available
in three apertures ranging from a highly portable 102 mm to a far-reaching 152mm,
these achromatic refractors produce stunning views of countless celestial treasures like
the Moon’s chiseled craters, Saturn’s elegant rings or the churning spiral of the face-on
Pinwheel Galaxy. To connect you with the cosmos, the doublet telescopes in this series
use a pairing of a crown glass lens and a flint glass lens separated by a cushion of air to
minimize chromatic aberrations. To further guarantee high-quality imagery, all optical
glass is fully multi-coated. Each model also offers a three-point collimation cell that
allows for pinpoint adjustments of the objective lens for precision performance. Your AR
Doublet Series telescope offers all of these benefits and more. This set-up manual and
the accompanying materials will guide you through a basic assembly process that will
have you at the eyepiece and under the stars in no time.
SUN WARNING
DO NOT use this telescope or any accompanying finder scope to look at or near the Sun!
Even momentary visual contact with the Sun’s light rays can instantly cause irreversible
damage to your eye(s). Eye damage can be painless, so there is no warning to the
observer that damage has occurred until it is too late.
Take extra care when using the telescope or a finder scope during daylight hours, and
do not point either at or near the Sun. Do not look through either when you are moving
the instruments during the daytime. Never allow anyone to use the telescope or a finder
scope during the daytime without warning them of the hazards of aiming either at or
near the Sun. Make sure that they are adequately trained on the use of these instruments
before allowing them to start observing. Children should always have informed and
trained adult supervision while observing.
PROPER CARE WARNING
Your telescope is a precision optical device and keeping the optics free of dust and dirt
is crucial for optimal performance. However, the use of improper cleaning techniques,
tools and/or solutions can cause irreparable damage to your telescope. In terms of
solutions, use distilled water and/or an optical glass cleaner that can be found at most
camera stores. Only use pure cotton swabs/balls or white, unscented, lotion-free tissues
for wiping down optics after you have removed as many particles as possible with forced
air or a photographic-grade camel hair brush. DO NOT use optical lens cleaning tissues
as many contain fiberglass particles that can be abrasive.
UNPACKING and MOVING
Please Note: We recommend that you keep the original shipping box and packing
materials if possible, in case your scope should ever need to be returned for service or
warranty purposes. When the box is opened for the first time, you will find that all parts
are packaged in plastic bags and the telescope’s tube is wrapped in tissue. To begin
assembly, slowly remove the optical tube. All models will come with their cradle rings
attached, which makes for easy removal. Rarely, the cradle could have come open during
packing or shipping, so it is important to check the latches and then do a quick, small lift
6
AR DOUBLET SERIES
by the cradle handle to make sure the ring is secure before pulling the instrument all the
way out. Although our telescopes are designed with portability in mind, it is important to
use proper lifting techniques to prevent back injury and/or strained muscles. Whenever
possible, use two people to move or lift the equipment and make use of wheeled devices
like carts or dollies for additional aid.
DEW SHIELD
The dew shield is an important part of your telescope because it slows moisture buildup on the objective lens and can reduce image interference caused by ambient light. On
each model in this series, the dew shield is pre-attached.
DIAGONAL
Astronomical observation usually requires the telescope to tilt up significantly, which
can make straight-thru viewing awkward and uncomfortable. A diagonal solves this
comfort problem by using a mirror to direct the light at a 90° angle toward the eyepiece,
which is positioned perpendicular to the optical tube assembly (OTA) making the image
more accessible. Equipped to fit both 1.25” and 2” eyepieces, your telescope’s diagonal
houses a precision-polished, two-inch mirror that is 99% reflective to maximize light
transmission. To install the diagonal, begin by removing the dust covers from the
focuser’s drawtube and the diagonal itself. Loosen the screws on the drawtube’s tension
collar, and slide the barrel of the diagonal into the drawtube. Tighten the three tension
screws to secure it firmly. Should one of these tension screws accidentally become loose,
the barrel of the diagonal is tapered to prevent it from falling out of the focuser. The
1.25” eyepiece adapter or 2” eyepieces can be secured in the diagonal by tightening the
tension screws on the compression ring lock. The 1.25” adapter also has a compression
ring to secure eyepieces that are inserted into it.
CRADLE RINGS
Please note: On our 102mm AR Doublet Achromatic Refractor, you will need to install
the finder scope before you put on the cradle ring assembly. On all of our other telescope
models, the finder scope can be installed after the cradle rings are in position.
To attach any of the AR Doublet models to a mount you will need to use the individual
model’s included cradle ring set. Engineered to snugly grip its particular telescope,
each extruded aluminum cradle assembly includes a hinged ring system, a slotted carry
handle and a felt-lined interior that protects the tube’s delicate surface. The rings are
attached to a dovetail saddle plate to secure your scope to a mount. To attach cradle
rings to your OTA, release the locking mechanism on each ring by loosening the metal
thumbscrews and then separate the rings. Position your OTA within the rings, close them
and retighten the thumbscrews until the tube is secure. If you are only repositioning
the tube, you probably will not need to remove the assembly completely. Instead, you
can undo the lock on each ring so that the tube is loose enough in the rings to slide back
and forth or rotate. Be careful to hold the tube securely so that you do not lose control
of it while the cradle rings are loose. Once the tube is in the desired position, be sure to
retighten each lock. Finding the right placement of the cradle ring assembly involves
finding your individual scope’s balance point, which depends largely on the accessories
you will be using. Before attempting to find this point, you should make sure the diagonal
7
AR DOUBLET SERIES
and/or any heavy attachments like cameras or large eyepieces are installed. You may
need to make adjustments for cone error if you are using a German equatorial mount.
Cone error occurs when the polar axis of your mount and the center of your telescope’s
optical axis are not aiming at the same point in the sky. To check for cone error, you
will need to first line your mount up with a fairly fixed point in the sky like Polaris or a
stationary terrestrial target that will be far enough away to see well in your telescope.
Mount your telescope and see if it is centered on the same target. If it is not, you will need
to take the scope off of the mount and slightly tilt the telescope tube away from or toward
the saddle plate by threading the adjusting screws in or out. These screws flank a central
locking screw on each end of the saddle plate. The process will take some trial and error
before the perfect adjustments are found. Please note that when the final adjustments
are made, the center locking screw must have enough engagement with the threads of
the cradle ring to make sure that the saddle plate stays connected.
Please note: On our 102mm AR Doublet Achromatic Refractor, you will need to install
the finder scope before you put on the cradle ring assembly. On all of our other telescope
models, the finder scope can be installed after the cradle rings are in position.
Each scope in our AR Doublet Series comes with a non-illuminated straight finder
scope: This classic reverse-view finder scope has a simple crosshair that can be centered
on your target. The first step in mounting your finder scope to your telescope is to slide it
into the finder scope bracket, which has two rings to hold your finder scope in place. Each
of these rings has three adjusting screws. If your finder scope is not already installed
in the bracket, loosen each of the adjusting screws until you have opened up the full
inside diameter of the rings. Slide the finder scope into place and gently tighten all of
the adjusting screws until your finder scope is secure. The bracket has a dovetail base
that slides easily into the mounting assembly that is already attached to the optical tube
assembly (OTA). Once it is installed in the base, secure it by tightening the two large,
heavy-duty plastic screws. For information on aligning your finder scope and telescope,
please refer to the finder scopes pamphlet.
8
ED TRIPLET ESSENTIAL SERIES
Welcome to our ED Triplet Essential Series
Designed to deliver crystal clear imagery rich in contrast, the premium telescopes in
our ED Triplet Essential Series are the ideal optical instruments to capture the universe’s
breathtaking sights. Available in three apertures ranging from a grab-and-go 80mm to
a versatile 127mm, these apochromatic refractors produce stunning views of countless
celestial treasures like the Moon’s chiseled craters, Saturn’s elegant rings or the
churning spiral of the face-on Pinwheel Galaxy. To provide you a true view of the cosmos,
the telescopes in this series feature an air-spaced triplet optical design that virtually
eliminates chromatic aberrations. In addition, they use a combination of genuine HOYA
extra-low dispersion (ED) glass and proprietary EMD enhanced multi-layer coatings
on all optical surfaces to generate brilliant high-contrast images with crisp definition.
The quality of the optics also allows those seeking to push magnification based on their
choices of eyepieces or focal extenders to do so without sacrificing clarity. To further
guarantee precision performance, these telescopes include a three-point collimation
cell that allows for pinpoint adjustments of the objective lens. Your ED Triplet Essential
Series telescope offers all of these benefits and more. This set-up manual and the
accompanying materials will guide you through a basic assembly process that will have
you at the eyepiece and under the stars in no time.
SUN WARNING
DO NOT use this telescope or any accompanying finder scope to look at or near the
Sun! Even momentary visual contact with the Sun’s light rays can instantly cause
irreversible damage to your eye(s). Eye damage can be painless, so there is no warning
to the observer that damage has occurred until it is too late. Take extra care when using
the telescope or a finder scope during daylight hours, and do not point either at or near
the Sun. Do not look through either when you are moving the instruments during the
daytime. Never allow anyone to use the telescope or a finder scope during the daytime
without warning them of the hazards of aiming either at or near the Sun. Make sure that
they are adequately trained on the use of these instruments before allowing them to start
observing. Children should always have informed and trained adult supervision while
observing.
PROPER CARE WARNING
Your telescope is a precision optical device and keeping the optics free of dust and dirt
is crucial for optimal performance. However, the use of improper cleaning techniques,
tools and/or solutions can cause irreparable damage to your telescope. In terms of
solutions, use distilled water and/or an optical glass cleaner that can be found at most
camera stores. Only use pure cotton swabs/balls or white, unscented, lotion-free tissues
for wiping down optics after you have removed as many particles as possible with forced
air or a photographic-grade camel hair brush. DO NOT use optical lens cleaning tissues
as many contain fiberglass particles that can be abrasive.
UNPACKING and MOVING
Please Note: We recommend that you keep the original shipping box and packing
materials if possible, in case your scope should ever need to be returned for service or
warranty purposes. When the box is opened for the first time, you will find that all parts
9
ED TRIPLET ESSENTIAL SERIES
are packaged in plastic bags and the telescope’s tube is wrapped in tissue. To begin
assembly, slowly remove the optical tube. All models will come with their cradle rings
attached, which makes for easy removal. Rarely, the cradle could have come open during
packing or shipping, so it is important to check the latches and then do a quick, small lift
by the cradle handle to make sure the ring is secure before pulling the instrument all the
way out. Although our telescopes are designed with portability in mind, it is important to
use proper lifting techniques to prevent back injury and/or strained muscles. Whenever
possible, use two people to move or lift the equipment and make use of wheeled devices
like carts or dollies for additional aid.
To begin assembly, slowly remove the optical tube from its foam casing. The 102mm,
127mm and 152mm models will all come with their cradle rings attached, which makes
for easy removal. Rarely, the cradle could have come open during packing or shipping,
so it is important to check the latches and then do a quick, small lift by the cradle handle
to make sure the ring is secure before pulling the instrument all the way out. Although
our telescopes are designed with portability in mind, it is important to use proper lifting
techniques to prevent back injury and/or strained muscles. Whenever possible, use
two people to move or lift the equipment and make use of wheeled devices like carts or
dollies for additional aid. Due to its necessary size and weight, the 152mm model’s case
comes with wheels for easier transport.
DEW SHIELD
The dew shield is an important part of your telescope because it slows moisture buildup on the objective lens and can reduce image interference caused by ambient light. We
advise using the dew shield when possible to maximize these crucial benefits. For the
80mm, 102mm and 127mm models, the dew shield is an easy-to-operate retractable
style that slides smoothly up and down the optical tube assembly with no installation
required.
DIAGONAL
Astronomical observation usually requires the telescope to tilt up significantly, which
can make straight-thru viewing awkward and uncomfortable. A diagonal solves this
comfort problem by using a mirror to direct the light at a 90° angle toward the eyepiece,
which is positioned perpendicular to the OTA making the image more accessible.
Equipped to fit both 1.25” and 2” eyepieces, your telescope’s diagonal houses a precisioninstall the diagonal, begin by removing the dust covers from the focuser’s drawtube and
the diagonal itself. Loosen the screws on the drawtube’s tension collar, and slide the
barrel of the diagonal into the drawtube. Tighten the three tension screws to secure
it firmly. Should one of these tension screws accidentally become loose, the barrel of
the diagonal is tapered to prevent it from falling out of the focuser. The 1.25” eyepiece
adapter or 2” eyepieces can be secured in the diagonal by tightening the tension screws
on the compression ring lock. The 1.25” adapter also has a compression ring to secure
eyepieces that are inserted into it. Please note: Your telescope may come with extension
tubes for situations in which you need more back focus. Please see the “Focusers” insert
for more information on how to install these accessories between the focuser and the
diagonal.
10
ED TRIPLET ESSENTIAL SERIES
CRADLE RINGS
(The following section does not apply to the 80mm model, as it does not include or need
a cradle ring. Instead, the 80mm has a vixen dovetail plate attached directly to the OTA.)
To attach the 102mm or 127mm model to a mount you will need to use the individual
model’s included cradle ring set.
Engineered to snugly grip its particular telescope, each extruded aluminum cradle
assembly includes a hinged ring system, a slotted carry handle and a felt-lined interior
that protects the tube’s delicate surface. The rings are attached to a saddle plate to
secure your scope to a mount. The cradles for the 102mm and 127 models have vixen
dovetail plates. To attach cradle rings to your OTA, release the locking mechanism on
each ring. On the 102mm model, the locking mechanism consists of a metal bar capped
with oversized thumbscrews. At the point where each half of the ring meets, simply flip
the bar over and tighten the thumbscrews. The 127mm model has an easy-to-operate
latching lock mechanism. If you are only repositioning the tube, you probably will not
need to remove the assembly completely. Instead, you can undo the lock on each ring
so that the tube is loose enough in the rings to slide back and forth or rotate. Be careful
to hold the tube securely so that you do not lose control of it while the cradle rings are
loose. Once the tube is in the desired position, be sure to retighten each lock. Finding
the right placement of the cradle ring assembly involves finding your individual scope’s
balance point, which depends largely on the accessories you will be using.
To begin assembly, slowly remove the optical tube from its foam casing. The 102mm
and 127mm models will come with their cradle rings attached, which makes for easy
removal. Rarely, the cradle could have come open during packing or shipping, so it is
important to check the latches and then do a quick, small lift by the cradle handle to
make sure the ring is secure before pulling the instrument all the way out. Although
our telescopes are designed with portability in mind, it is important to use proper lifting
techniques to prevent back injury and/or strained muscles. Whenever possible, use
two people to move or lift the equipment and make use of wheeled devices like carts or
dollies for additional aid.
11
CARBON FIBER SERIES
Welcome To Our ED Triplet Carbon Fiber Series
Designed to deliver crystal clear imagery rich in contrast, the premium telescopes
in our ED Triplet Carbon Fiber Series are the ideal optical instruments to capture the
universe’s breathtaking sights. Available in four apertures ranging from a grab-andgo 80mm to a far-reaching 152mm, these apochromatic refractors produce stunning
views of countless celestial treasures like the Moon’s chiseled craters, Saturn’s
elegant rings or the churning spiral of the face-on Pinwheel Galaxy. To provide you
a true view of the cosmos, the telescopes in this series feature an air-spaced triplet
optical design that virtually eliminates chromatic aberrations. In addition, they use a
combination of genuine HOYA extra-low dispersion (ED) glass and proprietary EMD
enhanced multi-layer coatings on all optical surfaces to generate brilliant high-contrast
images with crisp definition. The quality of the optics also allows those seeking to push
magnification based on their choices of eyepieces or focal extenders to do so without
sacrificing clarity. To further guarantee precision performance, these telescopes include
a three-point collimation cell that allows for pinpoint adjustments of the objective lens
and a carbon fiber optical tube assembly that eliminates focus change attributed to
shrinking or expansion caused by temperature fluctuations. Your ED Triplet Carbon
Fiber Series telescope offers all of these benefits and more. This set-up manual and the
accompanying materials will guide you through a basic assembly process that will have
you at the eyepiece and under the stars in no time.
SUN WARNING
DO NOT use this telescope or any accompanying finder scope to look at or near the Sun!
Even momentary visual contact with the Sun’s light rays can instantly cause irreversible
damage to your eye(s). Eye damage can be painless, so there is no warning to the
observer that damage has occurred until it is too late.
Take extra care when using the telescope or a finder scope during daylight hours, and
do not point either at or near the Sun. Do not look through either when you are moving
the instruments during the daytime. Never allow anyone to use the telescope or a finder
scope during the daytime without warning them of the hazards of aiming either at or
near the Sun. Make sure that they are adequately trained on the use of these instruments
before allowing them to start observing. Children should always have informed and
trained adult supervision while observing.
PROPER CARE WARNING
Your telescope is a precision optical device and keeping the optics free of dust and dirt
is crucial for optimal performance. However, the use of improper cleaning techniques,
tools and/or solutions can cause irreparable damage to your telescope. In terms of
solutions, use distilled water and/or pure isopropyl alcohol (99%). Do not eat, drink
or smoke while using this substance, wear protective gloves and eyewear, use in a
ventilated area and follow proper disposal techniques. Only use pure cotton swabs/balls
or white, unscented, lotion-free tissues for wiping down optics after you have removed
as many particles as possible with forced air or a photographic-grade camel hair brush.
DO NOT use optical lens cleaning tissues as many contain fiberglass particles that can be
abrasive.
12
CARBON FIBER SERIES
UNPACKING and MOVING
Please Note: We recommend that you keep the original shipping box and packing
materials if possible, in case your scope should ever need to be returned for service or
warranty purposes. Each model in this series comes packed in a deluxe case with springloaded butterfly latches and handles on both ends. After twisting all four latches open,
you will be able to fully remove the lid to reveal the molded interior that includes specific
spaces for all included accessories. When the case is opened for the first time, you will
find that all parts are packaged in plastic bags and the telescope’s tube is wrapped in
tissue. To begin assembly, slowly remove the optical tube from its foam casing. The
102mm, 127mm and 152mm models will all come with their cradle rings attached,
which makes for easy removal. Rarely, the cradle could have come open during packing
or shipping, so it is important to check the latches and then do a quick, small lift by the
cradle handle to make sure the ring is secure before pulling the instrument all the way
out. Although our telescopes are designed with portability in mind, it is important to
use proper lifting techniques to prevent back injury and/or strained muscles. Whenever
possible, use two people to
move or lift the equipment and make use of wheeled devices like carts or dollies for
additional aid. Due to its necessary size and weight, the 152mm model’s case comes with
wheels for easier transport.
DEW SHIELD
The dew shield is an important part of your telescope because it slows moisture buildup on the objective lens and can reduce image interference caused by ambient light. We
advise using the dew shield when possible to maximize these crucial benefits. For the
80mm, 102mm and 127mm models, the dew shield is an easy-to-operate retractable
style that slides smoothly up and down the optical tube assembly with no installation
required. On the 152mm model, the dew shield is stationary and must be attached using
the included set screws. To do this, remove the optical tube assembly from its case, take
off the front dust cover and gently slide off the dew shield, which is in a reverse position
during storage. During packaging, a foam padding is placed between the tube and the
dew shield. This can now be removed. Flip the dew shield around, reattach it to the front
of the tube and secure it by carefully tightening the three set screws. During breakdown,
simply reverse the process.
DIAGONAL
Astronomical observation usually requires the telescope to tilt up significantly, which can
make straight-thru viewing awkward and uncomfortable. A diagonal solves this comfort
problem by using a mirror to direct the light at a 90° angle toward the eyepiece, which is
positioned perpendicular to the OTA making the image more accessible. Equipped to fit
both 1.25” and 2” eyepieces, your telescope’s diagonal houses a precision-polished, twobegin by removing the dust covers from the focuser’s drawtube and the diagonal itself.
Loosen the screws on the drawtube’s tension collar, and slide the barrel of the diagonal
into the drawtube. Tighten the three tension screws to secure it firmly. Should one of
these tension screws accidentally become loose, the barrel of the diagonal is tapered to
prevent it from falling out of the focuser. The 1.25” eyepiece adapter or 2” eyepieces can
be secured in the diagonal by tightening the tension screws on the compression ring lock.
13
CARBON FIBER SERIES
CRADLE RINGS
(The following section does not apply to the 80mm model, as it does not include or need
a cradle ring. Instead, the 80mm has a vixen dovetail plate attached directly to the OTA.)
To attach the 102mm, 127mm or 152mm model to a mount you will need to use the
individual model’s included cradle ring set.
Engineered to snugly grip its particular telescope, each extruded aluminum cradle
assembly includes a hinged ring system, a slotted carry handle and a felt-lined interior
that protects the tube’s delicate surface. The rings are attached to a saddle plate to
secure your scope to a mount. The cradles for the 102mm and 127 models have vixen
dovetail plates, while the 152mm model has a Losmandy-style plate. To attach cradle
rings to your OTA, release the locking mechanism on each ring. On the 102mm model,
the locking mechanism consists of a metal bar capped with oversized thumbscrews.
At the point where each half of the ring meets, simply flip the bar over and tighten the
thumbscrews. The 127mm and 152mm models have an easy-to-operate latching lock
mechanism. If you are only repositioning the tube, you probably will not need to remove
the assembly completely. Instead, you can undo the lock on each ring so that the tube is
loose enough in the rings to slide back and forth or rotate. Be careful to hold the tube
securely so that you do not lose control of it while the cradle rings are loose. Once the
tube is in the desired position, be sure to retighten each lock. Finding the right placement
of the cradle ring assembly involves finding your individual scope’s balance point, which
depends largely on the accessories you will be using.
Before attempting to find this point, you should make sure the diagonal and/or any heavy
attachments like cameras or large eyepieces are installed. On the models with vixen
dovetail saddle plates attached to the cradle rings, you may need to make adjustments
for cone error if you are using a German equatorial mount. Cone error occurs when the
polar axis of your mount and the center of your telescope’s optical axis are not aiming at
the same point in the sky. To check for cone error, you will need to first line your mount
up with a fairly fixed point in the sky like Polaris or a stationary terrestrial target that will
be far enough away to see well in your telescope. Mount your telescope and see if it is
centered on the same target. If it is not, you will need to take the scope off of the mount
and slightly tilt the telescope tube away from or toward the saddle plate by threading the
adjusting screws in or out. These screws flank a central locking screw on each end of the
14
CARBON FIBER SERIES
saddle plate. The process will take some trial and error before the perfect adjustments
are found. Please note that when the final adjustments are made, the center locking
screw must have enough engagement with the threads of the cradle ring to make sure
that the saddle plate stays connected.
15
EYEPIECES
Introduction To Our Eyepieces
Your telescope’s eyepiece is more than a simple accessory. It sets the magnification
and field of view of your optical system and is a critical component in determining how
profoundly you connect with the cosmos. Designed to provide wide fields of view for a full
immersion experience, Explore Scientific’s premium eyepieces ensure stunning detail
with high-end optics that allow your telescope to reach its full potential. We offer five
series of eyepieces that differ in factors like field of view, available focal lengths, barrel
diameter and eye relief. However, they all share characteristics that guarantee superior
image quality. For peak performance, each of our precision eyepieces offers lenses made
of low-dispersion glass with a high refractive index. In addition, each lens is fully multicoated with durable enhanced multi-layer deposition (EMD) coatings. The combination of
these factors brilliantly captures the celestial wonders you seek with sharp contrast, high
resolution and crisp definition. To protect the precision optics, the body of each eyepiece
is O-ring sealed and purged with an inert gas (either argon or nitrogen) for a waterproof
environment that is impervious to internal fogging and prevents contaminants like fungus
and dust from entering. Each also offers foldable soft silicone rubber eyecups to provide
the most comfortable viewing experience and a filter thread on the backside that will
allow for use of moon or light filters.
FIELD OF VIEW
1,000m
125m
8x Binoculars
52.1˚
7.0˚
7.0˚
There are two distinct types of field of view to consider in any eyepiece. The first of
these is apparent field of view (AFOV). Expressed in degrees, the AFOV is the perceived
angle from your eye to the edges of the field stop of an eyepiece. The larger the AFOV,
the more area you will see. With AFOVs ranging from a wide 68° to a hyper-wide 120°,
our five lines of eyepieces will open up vast expanses of inky black sky for you to explore.
To provide views that are truly stunning, each eyepiece model is designed with the
distinct number and configuration of elements (optical lenses) needed to ensure a well
corrected field of view is maintained as the angle widens. The benefits of our wide field
eyepieces go beyond the amount they reveal. When you have more sky to work with,
objects are easier to locate and stay in the field of view longer, which translates to fewer
adjustments. This is especially helpful when you are using a non-driven mount. These
eyepieces also allow the viewer to use averted vision, which is a technique that aids in
observing faint objects. When using averted vision you gaze slightly to the side of your
target object rather than directly at it. This puts the image on a part of your eye that is
more sensitive to light, which allows you to enjoy fainter objects. The second type of
field of view is true field of view (TFOV), which is the actual field of view of the sky or
terrestrial scene expressed in degrees and/or fractions of a degree as seen through
a telescope/eyepiece combination. To calculate the TFOV, you will divide the apparent
field of view by the magnification. For example, if the resulting magnification from
your telescope and eyepiece set-up is 50x and your eyepiece has a 100° AFOV, you will
divide 100 by 50 to get a TFOV of 2°. TFOVs usually range between .25° to 2 degrees.
16
EYEPIECES
MAGNIFICATION
One of the main roles the eyepiece plays is setting the magnification or power of a
specific optical set-up. The amount of magnification you will want to use depends largely
on your subject. To calculate magnification, divide the focal length of the telescope by
the focal length of the chosen eyepiece. The resulting number will be your power. For
example, a 20mm eyepiece in a telescope with a 1,000mm 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. When choosing magnification, it is important
to remember that the lower the power the brighter the image. If you are observing the
Moon or a notable double star, a high power eyepiece will work well because the loss of
brightness that occurs as magnification amps up is not a huge factor. However, if you are
viewing a dim subject like an expansive galaxy or a faint nebula, you will want to use your
lowest power because you will need all of the brightness you can get. Overall, the best
way to determine what magnification level to use is to try different powers and see how
the image changes. Having a nice range of eyepieces available can be the most rewarding
way to enjoy all that the night sky has to offer.
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.
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 a astigmatism, because a long enough eye relief is necessary to allow room for
glasses. A full spectrum of eye relief distances is represented across our five eyepiece
lines.
OTHER ACCESSORIES:
FOCAL EXTENDERS
Available in 2x, 3x and 5x in a 1.25” barrel and 2x in a 2” barrel, our focal extenders add
versatility to your eyepiece line-up by allowing each eyepiece to perform at two powers.
For example, if your particular eyepiece/telescope combination results in a 50x power,
adding a 2x focal extender will change that to a 100x power. To guarantee superior
image quality, our focal extenders use multiple lens elements that are made of highquality glass and fully multi-coated with EMD coatings to reduce chromatic and spherical
aberrations. To use a focal extender, install it in the eyepiece barrel of your telescope/
diagonal before the eyepiece and then secure the eyepiece into it.
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EYEPIECES
COMA CORRECTOR
Coma is a common optical aberration that can plague the outskirts of your image.
When coma is present, stars in the center of the field will pop like precise points of light,
but stars at the edge take on an unnatural comet-like shape. Explore Scientific’s Coma
Corrector can help you minimize or even eliminate image aberrations caused by this offaxis optical phenomenon even in fast Newtonians. Our 2” coma corrector offers multicoated lenses, a black-anodized aluminum barrel with spacer markings and a textured
rubber grip. Tightly secured by three thumbscrews, this accessory comes with two
adapters (.75” and 1”) to secure to your T adapter and a protective cap.
FIELD FLATTENER
A curved focal plane is an inherent feature in most telescope designs and is nothing
to note for general stargazers. But, for astrophotographers, the consequences of that
same curved plane can ruin hours of patient imaging. Designed for refracting telescopes,
Explore Scientific’s Field Flattener can tackle the edge-of-field aberrations caused by
accessory offers fully multi-coated optics and slides securely into the 2” eyepiece holder.
FOCAL REDUCER
Explore Scientific’s 3” Field Flattener/.7x Focal Reducer is a multi-faceted accessory
designed to enhance your astrophotography experiences. As a field flattener, this piece
addresses the edge-of-field aberrations caused by curved focal planes to ensure your
night at the eyepiece will result in crisp, true images. As a focal reducer, this device will
reduce your f-ratio by .7, which results in a wider field of view, brighter images and less
exposure time. Recommended for our 127mm and 152mm refracting telescopes, and
is designed for f/7.5 to f/8.5 ratios and is best centered on a f/8 optical design, this field
flattener/focal reducer boasts fully multi-coated optics and comes with a 2” adapter to
accommodate different focuser sizes and two T-thread adapters.
18
FINDER SCOPES
Introduction To Our Finder Scopes
Finding a specific target in the vastness of the night sky can be a daunting and
frustrating task when the only tool at your disposal is a telescope. To help you hone in on
the celestial wonder you seek, a good finder scope that is properly aligned is a necessity.
Our eight-power 50mm finder scopes are designed to be precision optical instruments in
their own right. Outfitted with a fully multi-coated doublet main lens and a long eye-relief
eyepiece with a precision crosshair or reticle (depending on the model), our finder scopes
provide high resolution, high contrast images at low magnification to effortlessly and
quickly orient your telescope to a particular object or area of the sky. Although they share
a common mission to provide easy guidance, we do offer three distinct models. They are:
Non-Illuminated Straight Finder Scope: This classic reverse-view finder scope has a
simple crosshair that can be centered on your target. It features a front focus with locking
ring and a bright 6° field of view. Illuminated Straight Finder Scope: Explore Scientific’s
original straight-style, correct-image finder scope has a precision-etched illuminated
open circle, crosshair reticle with adjustable deep red LED illumination that makes target
acquisition easy. Precise focus of both the main objective lens and the eyepiece allow for
the sharpest views of the target being viewed as well as the reticle. The finder scope’s
correct-image, right-side-up viewing produces a natural view that benefits astronomy
and terrestrial observers. Polar Illuminated Right-Angle Finder Scope: In addition to
offering a right angle eyepiece for comfortable viewing and a larger 7° field of view, our
top model comes with an illuminated reticle that features northern and southern polar
reference markings for quick and precise polar alignments with any equatorial mount.
Although it has a larger 7° field of view, it shares the same attention to design and
features of the Illuminated Straight Finder Scope. These include adjustable brightness
for the reticle’s deep red illumination, precision focus of both the main objective lens and
the eyepiece and correct-image, right-side-up viewing.
SUN WARNING
DO NOT use a telescope or finder scope to look at or near the Sun! Even momentary
visual contact with the Sun’s light rays can instantly cause irreversible damage to your
eye(s). Eye damage can be painless, so there is no warning to the observer that damage
has occurred until it is too late. Take extra care when using a telescope or a finder scope
during daylight hours, and do not point either at or near the Sun. Do not look through
either when you are moving the instruments during the daytime. Never allow anyone to
use a telescope or a finder scope during the daytime without warning them of the hazards
of aiming either at or near the Sun. Make sure that they are adequately trained on the use
of these instruments before allowing them to start observing. Children should always
have informed and trained adult supervision while observing.
PROPER CARE WARNING
Your finder scope is a precision optical device and keeping the optics free of dust
and dirt is crucial for optimal performance. However, the use of improper cleaning
techniques, tools and/or solutions can cause irreparable damage to your scope. In terms
of solutions, use distilled water and/or an optical glass cleaner that can be found at most
camera stores. Only use pure cotton swabs/balls or white, unscented, lotion-free tissues
for wiping down optics after you have removed as many particles as possible with forced
air or a photographic-grade camel hair brush. DO NOT use optical lens cleaning tissues
19
FINDER SCOPES
as many contain fiberglass particles that can be abrasive.
FOCUSING YOUR FINDER SCOPE
(Please note: This section does not apply to our Non-Illuminated Straight Finder Scope,
which does not have a focus feature.) Our illuminated finder scopes allow for focus
adjustments of both the objective lens and the eyepiece.
On the Illuminated Straight Finder Scope, your initial focus adjustments can be made
before you mount the finder scope to your telescope. While holding the finder scope in
your hand, loosen the focus lock ring on the eyepiece by holding onto it while you turn the
eyepiece focus adjuster counterclockwise. Once the adjuster is moving freely, let go of
the lock ring and aim the finder scope at a blank wall. Turn the focus adjuster left or right
until you see the finder scope crosshairs reach perfect sharpness. Tighten the lock ring
down to hold the focus position
Now, loosen the objective lens focus adjuster in the same way. Aim the finder scope at
a very distant, stationary object. Turn the objective lens focuser left or right until you see
the object and the crosshairs reach perfect sharpness. Tighten the lock ring down to hold
the focus position.
Once your finder scope is mounted on your telescope, repeat the process on the Moon
or a bright star and make adjustments as necessary.
MOUNTING YOUR FINDER SCOPE
The first step in mounting your finder scope to your telescope is to slide it into the finder
scope bracket, which has two rings to hold your finder scope in place. Each of these rings
has three adjusting screws.
If your finder scope is not already installed in the bracket, loosen each of the adjusting
screws until you have opened up the full inside diameter of the rings. Slide the finder
scope into place and gently tighten all of the adjusting screws until your finder scope is
secure.
The bracket has a dovetail base that slides easily into the mounting assembly that
is already attached to the optical tube assembly (OTA). Once it is installed in the base,
secure it by tightening the two large, heavy-duty plastic screws.
Please note: On our 102mm AR Doublet Achromatic Refractor, you will need to install
the finder scope before you put on the cradle ring assembly. On all of our other telescope
models, the finder scope can be installed after the cradle rings are in position.
ALIGNING YOUR FINDERSCOPE
Once your finder scope is mounted on your telescope, it is time to align the finder scope
so that it and the telescope will be centered on the same spot in the sky when it is time to
use it. Although the process can be tedious, it is important to follow through to avoid later
frustrations that can ruin an observing session.
20
FINDER SCOPES
We recommend doing that first alignment in the daytime using a land-based target. Be
careful to do this in an area where you will not accidentally point either your telescope or
finder scope at or near the Sun, (see Sun Warning in this manual).
After you have set up your telescope and attached the finder scope, find an easy,
stationary target that is at least 200 meters away. We suggest using a streetlight or the
top of a telephone pole.
Insert your lowest power eyepiece into your telescope’s eyepiece holder and center the
chosen target in the telescope’s eyepiece. Look through the finder scope’s eyepiece and
loosen or tighten one or more of the adjusting screws that are located on the finder scope
rings until the crosshairs are precisely centered on the same target as the telescope.
Once you have reached the most accurate position, repeat the process with a medium
and a high power eyepiece in your telescope if possible. Once night falls, center the
Moon or a bright star in your finder scope then check the view in your scope. Make small
adjustments as needed.
USING YOUR ILLUMINATOR
(Please note: This section does not apply to our Non-Illuminated Straight Finder Scope.)
To turn your illuminator on, simply turn the top dial past the click stop. If you continue
to turn it clockwise, the illuminator will get brighter, but we recommend that you use it
at the dimmest setting that will still allow you to comfortably see the red-illuminated
crosshairs or polar reference markings (depending on which model you are using)..
CHANGING BATTERIES ON YOUR ILLUMINATOR
The batteries that power your finder scope’s illuminator should last for several hours
of continuous illumination, but we do recommend turning the illuminator off when not in
use to preserve battery life.
To change the batteries on your illuminator, unthread the illuminator from the finder
scope by grasping the entire unit and twisting it counterclockwise until it is free. Separate
the two halves of the illuminator by holding the two ends and twisting counterclockwise.
When the two halves are free of each other, carefully separate them so that the batteries
and the sleeve that holds them do not pop out uncontrollably.
Replace the old batteries with two new LR41 batteries and reinstall the sleeve, making
sure that the negative ends of the batteries are facing the LED illuminator.
Twist the halves back together and switch the illuminator on to make sure the batteries
are working. If the illuminator works, rethread it onto the finder scope. If not, check that
the polarity position is correct and that the batteries are new and fully charged. If the
illuminator still does not come on, clean the battery terminals with a pencil eraser and
try again. If the illuminator still does not respond, please contact our Customer Service
Department at (866) 252-3811 or online at www.explorescientificusa.com.
21
FOCUSERS
Introduction To Our Focusers
It takes more than excellent optics for your telescope to truly perform. If you want to
capture the intricacies of our Moon’s winding Hadley Rille or the spiraling arms of the
Pinwheel Galaxy, you will need to have a superior focuser in your astronomical arsenal.
The focuser is one of the most important mechanical components of your telescope
because it is the tool you use to find and hold that perfect crisp image. Although there are
differences in design, all four of our dual-speed focusers are built to meet high standards
of precision and functionality. We want to make sure you see the details you seek without
needing to make constant adjustments.
COMMON FEATURES
In addition to a shared mission to provide you the best viewing experience, each of our
focusers have some similar elements. These include:
• Fine and Coarse Focusing: On one side of each focuser you will find a stacked set of
dials. The largest of the pair controls your coarse focusing and the smaller provides
micro-focusing. Both controls are knurled so that you can grip them easily for smooth
adjustments even when you are wearing gloves.
• Locking and Tension Screws: Although they are located in different places on each
model, locking and tension screws perform vital functions on all of our focusers. To
avoid unintended adjustments, the locking screw can be gently tightened to keep the
focuser stationary once you have reached your desired focus. The tension screw(s) are
used to put pressure on the drawtube to secure it and keep it from sliding when heavier
accessories like cameras or large eyepieces are added.
• Tension Collar: At the end of each focuser, you will find a tension collar with three set
screws that are used to hold a diagonal or an eyepiece in place.
• Compression Ring Eyepiece Adapter: The purpose of this component is to allow you to
still use eyepieces/diagonals that are smaller than the diameter of the drawtube. Our
three 2” focusers include a 1.25” adapter, while our Feather Touch 3” focuser includes a
2” adapter. The adapter locks into place in the tension collar by tightening the collar’s set
screws.
STYLES OF FOCUSERS
Rack and Pinion Focuser
This focuser uses a circular gear (pinion) linked to the focus dials to move the drawtube
along a linear rack lined with teeth. As you turn the dial the gear engages with the teeth
guiding the drawtube in and out. On this 2” focuser, the locking screw is in the center
on the underside of the focuser and the two tension screws that press down to keep the
drawtube from slipping are on the top. This focuser is also rotatable, meaning that it can
be easily repositioned to change the position of the dials or to meet your specific comfort
or viewing needs. To use this feature, slightly loosen the tension screw on top of the
visual back adapter on your telescope tube that presses down on the focuser, rotate the
focuser and gently retighten the screw.
22
FOCUSERS
Crayford-Style Non-Rotatable Focuser
This focuser has a flat plane on the bottom side of the drawtube that rides along a roller
assisted by ball bearings to smoothly adjust the focus.
On this 2” focuser, the tension and locking screws are both located on the bottom of the
focuser, with the smaller of the two serving as the locking mechanism that holds the
focus dials stationary.
Crayford-Style Rotatable Focuser
This focuser has a flat plate installed on the bottom side of the drawtube that rides
along a roller assisted by ball bearings to smoothly adjust the focus.
On this 2” focuser, the tension and locking screws are both located on the bottom of
the focuser, with the center most of the two serving as the locking mechanism that
holds the focus dials stationary. This focuser is also rotatable, meaning that it can be
easily repositioned to change the position of the dials or to meet your specific comfort or
viewing needs. To use this feature, slightly loosen the tension screw on top of the visual
back adapter on your telescope tube that presses down on the focuser, rotate the focuser
and gently retighten the screw.
Feather Touch 3” Focuser
This special edition 3” Feather Touch focuser made by Starlight Instruments is
designed for use on our 152mm ED Triplet Carbon Fiber Telescope. It is an extremely
high-quality rack and pinion focuser. On the Feather Touch, the tension screw is located
on the top of the focuser, and the locking screw is on the bottom. This focuser is also
rotatable, meaning that it can be easily repositioned to change the position of the dials
or to meet your specific comfort or viewing needs. To use this feature, slightly loosen the
three tension screws on the visual back adapter on your telescope tube that press down
on the focuser. Rotate the focuser and gently retighten the screws.
INSTALLING YOUR FOCUSER
The following is the procedure you should follow to install your focuser if it was not
already on the telescope tube when you receive it or if you are changing focusers. One
end of the focuser has the tension collar that secures a diagonal or eyepiece to the
focuser. The other has a “lipped” end that fits directly into the visual back adapter on your
telescope tube. Once the focuser housing is inserted into the visual back adapter, gently
tighten down the set screws at the juncture to secure the focuser in place.
ADVANCED TENSION ADJUSTING TECHNIQUE FOR CRAYFORD-STYLE FOCUSERS
Most tension adjustments on our Crayford-style focusers can be easily accomplished by
using the tension screw on the bottom of each model. However, if you feel more tension
is needed, there are sets of small screws on the top of each device that can be used to
adjust the pressure that is coming down on the drawtube from above. To make these
adjustments, you will first need to loosen the button head screws (which are the largest
in the sets) using a hex wrench. For these screws, which serve as locking screws, you
will need a 2mm hex wrench for the Non-Rotatable Crayford-Style and a 2.5mm for the
Rotatable Crayford-Style. Once the button heads are loose, you can begin by carefully
23
FOCUSERS
tightening the four smaller screws equally using a 2mm hex wrench. It is important to
make sure each of the four screws is tightened the same amount to avoid giving the
drawtube an awkward and unbalanced tilt. Also be sure to make these adjustments in
very small increments. If you make these screws too tight, the drawtube will not glide
smoothly. If you make them too loose the drawtube will have difficulty maintaining its
position. Once you are done adjusting the smaller screws, retighten the larger locking
screws.
EXTENSION TUBES
Some observing situations and accessories require more back focus than your focuser
alone may be able to provide. Extension tubes aid in fixing this problem by extending the
length of the drawtube. To install extension tubes, unthread the tension collar at the end
of the focuser, thread the extension tube right onto the focuser tube and then rethread
the tension collar onto the end of the extension tube. Depending on your needs you may
want to use more than one extension tube. If that is the case, simply thread one tube
onto the other before replacing the tension collar. You can then install your diagonal or
eyepiece.
24
SHARE THE SKY
Share the Sky!
Awakening individuals to the marvels of the universe can be one of the most rewarding
aspects of owning a telescope.
When you share your eyepiece with others, you can witness their sense of wonder bloom
as they take in celestial spectacles like the chiseled lunar terrain, the elegant rings of
Saturn or the blue-white stars of the misty Orion Nebula for the first time.
Whether you are in your backyard, on a street corner or at a star party, by using your
telescope for outreach you are continuing a tradition started by Galileo more than
400 years ago. Since then, humanity’s understanding of the universe has grown at an
astounding pace, and much of that discovery can be linked to the desire to explore that is
born from looking through a telescope.
Founded in 2000, the Astronomy Outreach network (AOn) was created to encourage
and celebrate public outreach efforts by astronomers of all levels. This non-profit
organization has tasked itself with forging connections between individual astronomers,
astronomy clubs and larger astronomy and space education initiatives. No matter
where you are at in your journey to provide outreach, AOn is a great resource that can be
accessed at www.astronomyoutreach.net or through Facebook and Twitter.
As Carl Sagan said, “The Earth is a very small stage in a vast cosmic arena.” At the
eyepiece, the petty differences of humanity dissolve as our collective place in the universe
is put in perspective. We are on this “pale blue dot” together, and helping others realize
our common fragile bond is vital.
We encourage you to help others access the stars while you are on your own journey of
exploration. The mind-expanding experience you can share can truly make a difference
by inspiring others to discover more about the planet, the solar system, the galaxy and
the universe we all call home.
Visit www.astronomyoutreach.net today!
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NOTES
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NOTES
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