Orion EON 115 User manual

Orion®EON™115mm and
130mm ED Triplet
Apochromatic Refractors
#10285 EON 115
#10286 EON 130
IN 650 6/20
INSTRUCTION MANUAL
#10286
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may be reproduced, copied, modied or adapted, without the prior written consent of Orion Telescopes & Binoculars.
AN EMPLOYEE-OWNED COMPANY

2
Congratulations on your purchase of an Orion EON f/7 ED
Triplet Apochromatic Refractor! The EON 115mm and 130mm
ED Triplet apo’s have been designed with high-quality, preci-
sion ED optics and superior mechanical construction, making
them ideally suited to both high-performance imaging or visual
stargazing pursuits. These instructions will familiarize you with
the features of your instrument and how to use it.
WARNING: Do NOT look at the Sun without a
professionally made solar lter on the telescope;
serious eye damage may result if you look at the
Sun with any unltered optical instrument. Do not
leave the telescope unsupervised around children.
Always cover the lenses when leaving the telescope
in direct sunlight.
Contents
1. Parts List ............................. 2
2. Getting Started......................... 2
3. Features and Functions .................. 2
4. Operating the EON f/7 Triplet.............. 4
5. Care & Maintenance .................... 5
6. Specications.......................... 6
1. Parts List
• EON f/7.0 ED Triplet optical tube assembly
• Aluminum objective cap
• 1.25" eyepiece adapter
• Tube rings (pair)
• Dovetail mounting bar
• Hard case
2. Getting Started
The EON 115mm and 130mm ED Triplet apochromatic refrac-
tors come ready for use from the factory. Your telescope’s
optics have been assembled and precisely collimated at the
factory, so they should not require any adjustments. Please
keep the original shipping box. In the unlikely event that you
need to ship the telescope back to Orion for warranty repair
service, you should use the original packaging.
3. Features and Functions
The EON f/7 Triplet has premium features designed to maxi-
mize the performance of the scope and its convenience of
use. Please refer to Figure 1 to become familiar with the tele-
scope’s features.
Figure 1. Features and components of the EON Triplet apochromatic refractor
Dovetail mounting bar
Fine focus knob
Coarse focus knob
Drawtube tension
knob
2" accessory
collar
2.5" Rack and
Pinion focuser
Dovetail nder
scope base (shoe)
Tube rings
Retractable dew shield
Objective lens cover
1.25" adapter
Focuser rotation interface

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Retractable Dew Shield
The dew shield of the EON 115mm and 130mm is retractable,
allowing the telescope to become more compact for storage.
To extend the dew shield, simply grasp and slide it out until it
is fully extended.
2.5" Dual-Speed Crayford Focuser
Focusing the EON is truly a joy, thanks to the all-machined,
extra-large 2.5" Rack and Pinion focuser (Figure 2). It provides
exceptionally smooth, backlash-free focus motion and excel-
lent rigidity for holding heavy imaging trains without exure or
slippage. The 2.5"-diameter drawtube ensures that even full-
frame imaging sensors will have a generously large fully illumi-
nated eld. A drawtube tension knob is located on the under-
side of the focuser (Figure 2B).
The dual-speed (10:1) focusing mechanism will keep your tar-
get object crisp and sharp. For quick focusing, the two large
focus knobs provide a coarse focus. For more precise focus-
ing, as needed for applications such as high-power planetary
observing and imaging with a CCD or digital camera, the
smaller focus knob on the right side (Figure 2A) offers an 10:1
ne focus adjustment (~10 turns of the ne focus knob equal 1
turn of the coarse focus knob).
If you nd that the focus motion feels too stiff or if, on the con-
trary, the drawtube slips easily under the weight of your eye-
piece or camera, you can make adjustments to the focuser
tension with the focuser tension thumbscrew located on the
bottom side of the focuser (Figure 2B). Adjust this thumbscrew
until the focuser motion feels smooth and the drawtube holds
in place under load when you have obtained focus. It may
be necessary to make adjustments when the weight of your
accessories changes signicantly.
Engraved Millimeter Scale on Focuser Drawtube
The drawtube of the EON's focuser features a laser-engraved
millimeter scale on top, which aids in providing repeatable
focus. When precise focus is achieved, noting the value on the
scale where the drawtube meets the focuser housing will allow
you to return to approximately the same point, such as when
focusing the same camera in subsequent imaging sessions.
Using the scale can save time compared to nding the focus-
ing point “from scratch.”
Focuser Rotation
The focuser on the EON 115mm and 130mm features a rotat-
able component. The entire focuser can be rotated just behind
the collar where the focuser attaches to the optical tube (see
Figure 2A). To rotate the focuser, loosen the rotation lock
thumbscrew (Figure 2A) a turn or so counterclockwise. Gently
rotate the focuser to the desired orientation, then lock it in
place by turning the lock thumbscrew clockwise. If you nd the
focuser is difficult to rotate, you may have to very slightly loos-
en the three rotation tensioning setscrews around the focuser
with a at head screwdriver. If, on the other hand, you feel too
much “play” in the focuser when the thumbscrew is loosened,
you may need to tighten these setscrews a bit.
NOTE: If you do not plan to use the rotation interface, we
recommend tightening down the adjacent three setscrews
as well as the thumbscrew lock for the most secure ex-
free optical tube.
Finder Scope Dovetail Shoe
The EON’s focuser is equipped with a dovetail nder scope
shoe that allows attachment of an optional Orion nder scope,
reex sight, mini guide scope, or the Orion Dual Finder Scope
bracket (Figure 2A).
Using 1.25" and 2" Accessories
Your EON refractor can accommodate both 1.25" and 2"
accessories, including just about any eyepiece, diagonal, or
camera. The focuser has a 2" accessory collar attached to the
drawtube. This collar features a non-marring rotating com-
pression-style system and a thumbscrew for added security
when attaching a diagonal or other 2" accessory. The included
A.
B.
Figure 2. The 2.5" Rack and Pinion focuser used on both
the EON 115 and 130 A) Top side, B) bottom side
Coarse
focus
knob
Fine focus
knob
2" Accessory
locking security
thumbscrew
2" Accessory
locking collar
Dovetail
nder scope
base (shoe)
Rotational
lock
thumbscrew
1.25" adapter
locking collar
Rotational
interface
Focus tensioning
thumbscrew
Rotation tensioning
setscrew (x3)
Rotation
tensioning
setscrew (x3)

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2"-to-1.25" step-down adapter is also equipped with a rotat-
ing brass compression system to prevent scoring of your 1.25"
accessory. The telescope must be used with either a diagonal
or extension tube in order for an eyepiece to reach focus. In
most cases, you will be using a 90° star diagonal for visual use
with an eyepiece. A camera will also likely require a 2" exten-
sion adapter to reach focus. An optional eld attener can be
used instead of an extension adapter, and is recommended for
imaging with cameras having an APS-C sized sensor or larger.
To attach a 1.25" diagonal to your telescope:
1. Rotate the collar on the 1.25" adapter counter-clockwise
to loosen the compression system.
2. Remove the dust cap from the 1.25" eyepiece adapter.
3. Insert the barrel of your diagonal or extension tube into
the 1.25" eyepiece adapter.
4. Secure the barrel in place by rmly rotating the collar
clockwise on the 1.25" eyepiece adapter to engage the
compression locks
To attach a 2" diagonal, or extension tube to your telescope:
1. Loosen the security thumbscrew on the focuser’s
2" accessory collar and rotate the 2" collar counter-
clockwise to unlock the compression system.
2. Remove the 1.25" eyepiece adapter.
3. Insert the barrel of your diagonal or extension tube into
the 2" accessory collar.
4. Secure the barrel in place by rmly rotating the
compression collar clock-wise
5. Engage the security thumbscrew to rmly lock the system
in place.
4. Operating the EON f/7
Triplet
The EON 115mm and 130mm Triplet refractors are versatile
telescopes designed for both high-performance imaging and
visual pursuits. Their moderate f/7 focal ratio and premium ED
optics combine to make them especially effective instruments
for imaging with CCD or DSLR cameras.
Now that you have become familiar with the different features
and functions of the telescope, you are ready to begin using
it outside under a starry sky. Be sure to allow the telescope
to equilibrate to the outdoor temperature for at least ½ hour
before using it; this ensures the best image quality.
Connecting the EON to a Telescope Mount
The EON 115mm and 130mm Triplet refractors come with a
pair of sturdy, hinged and felt-lined tube rings and a Vixen-style
dovetail mounting bar. The tube rings have a large clamp knob
to secure them tightly on the telescope tube. The rings also
have multiple M6-1.0 threaded holes on the top and bottom
bosses for attachment of dovetail bars or plates for coupling
the telescope to a mount (on the bottom) and for piggybacking
a guide scope or second imaging or visual telescope on top of
the EON.
Balancing the telescope can be done by moving the telescope
forward or backward within the tube rings, or by sliding the
dovetail mounting plate forward or backward in your mount’s
saddle.
Extending the Dew Shield
The dew shield on the EON refractors should be extended prior
to use of the telescope. The dew shield reduces the formation
of dew on the outside surface of the objective lens and blocks
off-axis ambient light from entering the telescope, which could
reduce contrast and cause internal reections. To extend the
dew shield, simply slide the dew shield forward until it stops.
Don’t forget to retract the dew shield before attempting to store
the tube in the included case.
Observing with the EON f/7 Triplet
To observe with the EON 115mm or 130mm Triplet you will
need either a 1.25" or 2" diagonal and an eyepiece, each sold
separately. Because the optics are made with high-quality ED
glass, the eyepieces you choose should also have excellent,
fully multi-coated optics to leverage the full performance of the
telescope. It is desirable to have a range of eyepieces of differ-
ent focal lengths, to allow viewing over a range of magnica-
tions.
To calculate the magnication, or power, of a telescope, simply
divide the focal length of the telescope by the focal length of
the eyepiece:
Magnication = Telescope Focal Length (mm)
Eyepiece Focal Length (mm)
If outside viewing conditions are ideal, a telescope with good
optics can achieve a magnication of about 60x per inch, or
2.4x per millimeter, of aperture. Keep in mind that at higher
powers, an image will always be dimmer and less sharp (this
is a fundamental law of optics). In most cases the steadiness
of the air (the “seeing”) will limit how much magnication the
scope can tolerate, rather than the telescope itself.
Always start viewing with your lowest-power (longest focal
length) eyepiece in the telescope. After you have located and
observed the object with it, you can try switching to a higher-
power eyepiece to ferret out more detail, if atmospheric con-
ditions permit. If the image you see is not crisp and steady,
reduce the magnication by switching to a longer focal length
eyepiece. As a general rule, a small but well-resolved image
will show more detail and provide a more enjoyable view than
a dim and fuzzy, over-magnied image.
Imaging with the EON f/7 Triplet
Given their high-quality f/7 apochromatic optics, the EON
115mm and 130mm Triplets excel for astrophotography with
a CCD or DSLR camera. To attach a DSLR camera, all you
will need is the appropriate T-ring for the make and model of
your camera, a 2" prime focus camera adapter or T-adapter,
and (for the EON 130 only) a 2" extension tube (available from
Orion). Simply attach the T-ring to the camera body and thread
the 2" prime focus camera adapter onto the T-ring. Insert the
barrel of the camera adapter into the 2" extension tube, then
install the 2" extension tube in the 2" accessory collar of the
focuser and secure it with the thumbscrews.

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For the EON 115, no extension tube is needed. Just thread the
T-ring for your specic DSLR camera onto the T-adapter and
insert the barrel of the T-adapter into the 2" accessory collar of
the focuser and secure it with the thumbscrews
Most CCD/CMOS cameras will have a 1.25" or 2" barrel ready
to attach directly to your telescope like an eyepiece or diago-
nal. No adapter is required, simply insert the barrel of the cam-
era into the 1.25" adapter or 2" accessory collar and secure
the camera with the locking collar. Depending on your cam-
era, you may need to use an extension tube for your particular
imaging setup. Any imaging accessory, such as a color lter
wheel, increases the amount of inward focus travel required.
An optional eld attener is a desirable accessory to compen-
sate for the inherent eld curvature of optically fast, or mod-
erately fast, refractors such as the EON 115 and 130. Orion
carries a eld attener designed for use with both the EON
115 and 130; see our website or call Orion customer service
for more information. The attener will ensure tight, sharp stars
out to the edge of your imaging sensor, and is highly recom-
mended if you are using a camera with an APS-C size sensor
or larger. For visual use, a eld attener may not be necessary.
For imaging sensors smaller than APS-C used with the EON, a
eld attener may not provide any noticeable benet.
Note about Chromatic Aberration
Chromatic aberration literally means color distortion. Whenever
light passes through one material to another, different wave-
lengths (color) are bent by different amounts. This is a prob-
lem that plagues refractor-type telescopes, since light passes
through both air and glass to form an image. Most astronomi-
cal objects emit a spectrum comprised of many different wave-
lengths of light, so each wavelength will be bent by a slightly
different amount when passing through a lens. This results in
each color of light reaching precise focus at a slightly different
point, which will provide a soft image with a halo of unfocused
color.
The EON Triplet apochromatic refractors are designed to mini-
mize chromatic aberration. The three-element, air-spaced lens
assembly includes one element made from high-performance
FK-61 “extra-low dispersion”, or ED, glass. The use of this ED
glass largely eliminates chromatic aberration, resulting in a
much more pleasing view as compared to typical achromatic,
or two-element, refractors. Critical stellar or planetary observa-
tions become more accurate with this color correction since
the focus is sharper, with no unfocused “false” color around
the object. The ED triplet optics will render true, high-contrast
images
5. Care & Maintenance
Give your telescope reasonable care and it will last a life-
time. When not in use, keep the telescope in its padded case
(Figure 3), and keep the objective dust cover on, as well as
the small plastic plug on the 1.25" adapter. Store it indoors or in
a dry garage. Do not leave the telescope outside except when
using it. If a scratch appears on the tube, it will not harm the
telescope. Smudges on the tube can be wiped off with stan-
dard household cleaners.
Dew
When you are ready to pack up your telescope at the end
of the night, avoid immediately storing it if you encountered
heavy dew and the telescope is damp. Instead, bring the tele-
scope inside and allow the moisture on the telescope to evap-
orate. If dew forms on the objective lens, then leave the dust
cover off of the telescope until all the moisture has evaporated.
Once the telescope has completely dried out, place it back in
its case.
Cleaning Optical Surfaces
In general, your telescope will only need to be cleaned on a
very minimal basis. Dust particles on the objective lens do not
affect the optical quality of your EON. Loose dust can simply
be blown off with air, using a compressed air can or blower
bulb. Any remaining dust is best left alone, unless the build up
is extreme. Fingerprints and water marks should be cleaned
from your telescope’s objective lens. Any quality optical lens
tissue and cleaning uid specically designed for multi-coated
optics can be used to clean the telescope’s objective lens as
well as the lenses of your eyepieces and nder scope. Never
use regular glass cleaner, or cleaning uid designed for eye-
glasses.
Before cleaning with uid and tissue, however, blow any loose
particles off the lens with a blower bulb or compressed air, or
lightly brush the lens with a soft camel hair brush. Apply some
cleaning uid to a tissue, never directly on the optics. Wipe the
lens gently in a circular motion, then remove any excess uid
with a fresh lens tissue. Oily ngerprints and smudges may be
removed using this method. Use caution; rubbing too hard may
scratch the lens! Clean only a small area at a time, using a
fresh lens tissue on each area. Never reuse tissues.
Figure 3 The foam-tted hard case keeps the EON telescope
clean and well-protected. (EON 115 shown)

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6. Specifications
EON 115 f/7 ED Triplet
Optical tube: Seamless
aluminum
Optics: Air-spaced
Triplet, with one element FK-61 ED
Lens cell: Machined
aluminum
Aperture: 115mm (4.52")
Tube color: Gloss white
Focal length: 805 mm
F-ratio: 7.0
Lens coatings: Fully multi-coated (all air-to-glass surfaces multi-layer coated)
Tube baffles: Multiple knife edge baffles
Tube length,dew shield retracted: 27.5" / 69.9 cm
Tube length, dew shield extended: 34.4" / 87.4 cm
Weight: (with tube rings and
dovetail bar attached) 22.5 lbs. (with tube rings attached)/ 10.2 kg
Tube rings: Split, felt lining, three M6x1.0 holes on upper and lower bosses
Focuser: 2.5" Rack and Pinion, 10:1 dual speed
Drawtube travel: 3.75" / 95mm
Rotatable focuser: Yes
Dew shield: Retractable
Finder scope: Optional; installed dovetail nder scope shoe
2" accessory collar: Rotating compression lock
1.25" adapter: Rotating Brass compression lock
Objective dust cover: Aluminum, slip t
Diagonal: Not included
Eyepiece: Not included
Field attener: Optional
Case: Hard case with die-cut interior, outer dimensions 36.75" x 11.25" x 12.25"

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EON 130 f/7 ED Triplet
Optical tube: Seamless aluminum
Optics: Air-spaced Triplet, with one element FK-61 ED
Lens cell: Machined aluminum
Aperture: 130mm (5.12")
Tube color: Gloss white
Focal length: 910 mm
F-ratio: 7.0
Lens coatings: Fully multi-coated (all air-to-glass surfaces multi-layer coated)
Tube baffles: Multiple knife edge baffles
Tube length,dew shield retracted: 32" / 81.3 cm
Tube length, dew shield extended: 38" / 96.5 cm
Weight: (with tube rings and
dovetail bar attached) 20.7 lbs. / 9.49 kg
Tube rings: Two hinged, felt lined rings, multiple M6-1.0 holes top and bottom
Focuser: 2.5" Rack and Pinion, 10:1 dual speed
Drawtube travel: 3.75" / 95mm
Rotatable focuser: Yes
Dew shield: Retractable
Finder scope: Optional; installed dovetail nder scope shoe
2" accessory collar: Rotating compression lock
1.25" adapter: Rotating Brass compression lock
Objective dust cover: Aluminum, slip t
Diagonal: Not included
Eyepiece: Not included
Field attener: Optional
Case: Hard case with die-cut interior, outer dimensions 36.75" x 11.25" x 12.25"

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One-Year Limited Warranty
This Orion product is warranted against defects in materials or workmanship for a period of one year from
the date of purchase. This warranty is for the benet of the original retail purchaser only. During this war-
ranty period Orion Telescopes & Binoculars will repair or replace, at Orion’s option, any warranted instru-
ment that proves to be defective, provided it is returned postage paid. Proof of purchase (such as a copy
of the original receipt) is required. This warranty is only valid in the country of purchase.
This warranty does not apply if, in Orion’s judgment, the instrument has been abused, mishandled, or
modied, nor does it apply to normal wear and tear. This warranty gives you specic legal rights. It is not
intended to remove or restrict your other legal rights under applicable local consumer law; your state or
national statutory consumer rights governing the sale of consumer goods remain fully applicable.
For further warranty information, please visit www.OrionTelescopes.com/warranty.