ORION TELESCOPES & BINOCULARS EON 10383 User manual

Orion®EON™70mm ED
Quadruplet Astrograph
Refractor Telescope
#10383
Congratulations on your purchase of the Orion 70mm ED Quadruplet Astrograph Refractor!
The EON has been designed with exceptionally high quality,precision ED optics and superior
mechanical construction, making it ideally suited to high-performance imaging with today’s
larger format CCD and CMOS cameras.These instructions will familiarize you with the features
of your instrument and how to use it.
IN 650 6/20
INSTRUCTION MANUAL
Corporate Offices: 89 Hangar Way, Watsonville CA 95076 - USA
Toll Free USA & Canada: [phone]
International: [phone]
Customer Support: [email protected]
Copyright © 2022 Orion Telescopes & Binoculars.All Rights Reserved. No part of this product instruction or any of its contents
may be reproduced, copied, modied or adapted, without the prior written consent of Orion Telescopes & Binoculars.
AN EMPLOYEE-OWNED COMPANY

2
1. Parts List
• EON 70mm ED Quadruplet Refractor
• Objective lens cap
• Focuser end cap
• Tube rings (pair)
• Lower mounting dovetail bar
• Upper accessory rail
• Dovetail nder scope base
• 54mm-48mm step down ring (includes 48mmx0.75mm lter
threads)
• 48mm-42mm step down ring (not shown)
• Hard case with custom foam interior
The EON 70mm ED Quadruplet refractor comes 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
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.
2. Features and Functions
Your EON 70mm Quadruplet has premium features designed
to maximize the performance of the scope for imaging the night
sky. Most notably, the air-spaced four-element designed objec-
tive lens contains Hoya FCD100 extra-low dispersion (“ED”)
glass, which minimizes chromatic aberration and also provides
a very well corrected at eld of view for impeccably clean, sharp,
high-resolution images without the need for extra eld atten-
ing lenses.
Retractable Dew Shield
The dew shield of the EON 70mm Quad is retractable, allowing
the telescope to become more compact for storage. To extend
the dew shield, simply pull it forward until it stops. Extend the
dew shield while imaging to block extraneous light and to fore-
stall the formation of dew on the exposed surface of the objec-
tive lens. If you look closely at the back end of the dew shield
bevel, you will nd three small allen head setscrews (Figure 1),
which can be slightly tightened down to secure the dew shield in
place. Under normal operation this shouldn’t be necessary, but
if you use a light box to lay over the dew shield when the tele-
scope is pointed straight up in order to capture at eld calibra-
tion frames, tightening these setscrews down will prevent the
dew shield from contracting under the weight of the light box.
Don’t forget to loosen these setscrews slightly before retracting
the dew shield.
Dual-Speed Focuser
The 70mm Quad features an incredibly well build 3" rack-and-
pinion focuser with 10:1 reduction gearing, and bias (diagonal)
cut on the rack to provide exceptionally smooth, backlash-free
Figure 1. Features and parts of the EON 70mm ED Quadruplet Astrograph
54mm female threads
Vixen dovetail bar
Top accessory rail
Focus knob (dual speed knob opposite side)
Dew shield locking setscrews
(3x around perimeter
Finder dovetail shoe
Retractable dew shield
54mm-48mm
adapter
Camera rotation lock knob

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focus motion and excellent rigidity for holding heavy imag-
ing trains. This rack-and-pinion design is superior to Crayford
designs because there is no possibility of focuser slip with
heavier loads or pointing high in the sky – critical when trying
to obtain precise and repeatable focus, especially when using a
robotic focus motor. Speaking of which, the focus knob on the 1:1
side is removable, revealing the 6mm diameter focus shaft below.
This makes the focuser compatible with 3rd party electronic/
robotic motors that include a universal adapter in order to attach
to the focuser housing. To remove the focus knob, use a 2mm
allen wrench to remove the cover setscrew (closest setscrew to
the black focus knob), and then rotate the focus knob while look-
ing through this hole to nd the shaft lock setscrews. Loosen this
screws, and the focus knob will slip off. Do not attempt to remove
the 10:1 reduction gear side of the focuser.
The focuser itself features a 29.5mm travel distance, and the
light comes to focus 69.5mm behind the 48mm threads when
the focuser is fully rotated inward. This should help you gauge
what spacing adapters you may need for your specic camera
combination.
To attach your camera, lter-wheel, or off-axis guider, you’ll need
to thread it directly onto the focuser. This telescope does not
use a 2" or 1.25" slip t eyepiece hole like visual telescopes
– the thread-on connection is much more robust and ex free
for obtaining the highest quality images. In order to be compat-
ible with the most amount of camera gear on the market, we
include several adapter rings. First, native to the 70mm focuser
is a 54mm x 0.75mm thread pitch female thread. From there,
you can step down to a male 48mm x 0.75mm “wide-t” thread,
and from that, even further down to the 42mm x 0.75mm thread
pitch standard t-thread. Cameras such as our StarShoot G10 and
G26 utilize 42mm threads, and larger camera and accessories
(such as our G24 Full Format camera and Nautilus lter wheel),
can utilize the 48mm threads. Some larger camera/accessories
may even utilize the full 54mm female thread on the focuser, but
depending on the specic situation and components, you may
need to purchase extra imaging adapter rings which are widely
available on the internet.
Camera Rotation
The focuser on the 70mm Quad allows full rotation of the camera.
Rotating the camera can be useful for framing an imaging target
on a camera’s sensor for the perfect composition.The 70mm has
a rotation interface directly behind the 54mm threads, in front of
the drawtube (Figure 1).To rotate the camera, simply loosen the
large rotation lock thumbscrew slightly, rotate the camera to the
desired angle, and then tighten down the thumbscrew again. Be
sure when rotating the camera, that you are NOT unthreading it
from the focuser itself!
Finder Scope Dovetail Shoe
Your EON 70mm Quad comes with a dovetail nder scope shoe
(Figure 1) that allows attachment of an optional Orion nder
scope, reex sight, mini guide scope, or the Orion Dual Finder
Scope bracket. Simply loosen the locking thumbscrew, slide your
nder in until it is fully seated or centered, and then lock the
thumbscrew back down.
Tube Rings and Mounting plates
Your EON 70mm refractor comes with a pair of heavy duty, CNC-
machined, clamp-style tube rings (Figure 2). Each has a at boss
on the top and bottom with multiple threaded M6 (6mm diameter
x 1mm thread pitch) holes on the top, bottom, and even sides,
for attachment of accessories. Also included is a bottom Vixen
shaped mounting plate made of machined and anodized alumi-
num. This allows the EON to attach to any mount compatible
with the Vixen dovetail system.And if you have a Losmandy style
mount head, Orion offers an optional adapter plate to allow use
of the Vixen dovetail bar in the wider Losmandy cradle.
The top dovetail bar/handle of the 70mm Quad features an
Arca-Swiss dovetail cut into the edge which is a popular dove-
tail shape in the larger photography industry.There are multiple
M6 threaded holes on the top of this bar (except the center hole
is ¼"-20), as well as on the side of the rings that will allow you to
attach any number of accessories to the tube.
Hard Case
The hard case that comes with your EON should be used to
transport and store the telescope when it’s not in use, to keep
the instrument clean and protected from damage.
3. Using Your Camera with
the EON 70mm Quadruplet
Because of the 4-element design of this astrograph, you do NOT
need to use a separate eld attener in order to achieve sharp
images in the corners of your eld.The best part of this feature is
that you do not need to worry about achieving the dreaded and
exacting 55mm spacing between you camera sensor and the
Figure 2. The hinged tube rings

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eld attener. Simply attach you camera (making sure the focus
point is within the range of the focuser), and the resulting image
will be very well corrected.
Finding focus can be a bit difficult the rst time out, since there
are so many different combinations of camera and accessory
gear that can attach. A little time spend during the day with the
back focus data of your specic camera and gear and a calcula-
tor can make life much easier.
Focus distance example
Remember, the focuser has a 29.5mm range of travel, but your
camera sensor has to sit 69.5mm back from the 48mm threads.
So for example, the StarShoot G24 has a 17.5mm back focus
from the front threads of the camera body, and also includes
a 21mm and 16mm spacer. So 17.5mm + 21mm + 16mm =
54.5mm. Since the EON focuses 69.5mm behind the 48mm
threads, 69.5mm – 54.5mm = 15mm. This means the focuser
should be racked out approximately 15mm in this conguration
to reach focus – well within the travel range of the focuser itself.
If you have a lter wheel attached to the front of the camera,
simply add the depth of the lter wheel to the back focus of the
camera in order to get the new back focus of your camera/lter
wheel combo. It is highly likely that in many camera combina-
tions, especially without a lter wheel or off-axis guider in front of
the camera, that you may need extra extension tubes in order to
reach focus. Orion offers 42mm t-ring spacers (#5528) and 48mm
spacers (#52715) in order to help achieve focus with any number
of different cameras. If you are using an Orion StarShoot G10,
G26 or similar cameras that do not include extra spacer rings
and you are also not using an off-axis guider and/or lter wheel,
it is recommended you purchase some of these extension rings
to ensure you can adequately reach focus. Note: if you are using
a DSLR, most all have a 55mm back focus, so they should work
without any extra adapters or spacers necessary.
Note about edge performance: The optics are extremely well
corrected for atness of eld out to the 43mm image circle periph-
ery. In fact, it is better corrected than any improvement an add-on
eld attener would normally provide with a standard refractor.
However, as the camera sensor and eld of view get bigger,
there is always a tradeoff with edge of eld performance.With an
APS-C size sensor, the eld of view is ~3.8 x 2.6 degrees, and
the edge performance is quite excellent. With a 35mm format
camera, you will be pushing to the edge of the image circle with
a massive eld of view of ~5.9 x 3.9 degrees. The edge perfor-
mance is still very good, but perhaps not quite as perfect as with
a smaller APS-C sensor.
Filter Pocket Threads
Normally, lters would go into a lter wheel installed between the
camera and the telescope, and that works perfectly well with the
70mm, especially if you use the Nautilus Filter Wheel.The Nauti-
lus is compatible with all Orion brand lters, and many lters on
the market that use the nominal 0.6mm thread pitch. But there
is a growing number of vendors who utilize the camera attach-
ment thread pitch (0.75mm) for some of their 2" lter threads,
so we’ve included a female “wide” t-thread on the inside of the
54mm – 48mm adapter. Look into the “sky” end of this adapter
ring, and you’ll nd female threads, which would match to a lter
that uses 48mm x 0.75mm thread pitch (Figure 3).
4. Care & Maintenance
Give your refractor reasonable care and it will last a lifetime.
When not in use, keep the telescope in its padded case and keep
the objective dust cover on, as well as the cap on the focuser end.
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 standard household cleaners.
Dealing with 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 telescope inside
and allow the moisture on the telescope to evaporate. If dew
forms on the objective lens, then leave the dust cover off of the
telescope until all the moisture has evaporated. Once the tele-
scope 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 tele-
scope’s objective lens.Any quality optical lens tissue and clean-
ing 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 eyeglasses.
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
Figure 3. The Filter pocket threads inside the 54mm-48mm
adapter (NOTE, 48mm-42mm adapter ring not shown).
48mm x 0.75mm
female lter threads

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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.
6. Specifications
Optical tube: Seamless aluminum
Optics: Air-spaced quadruplet, including Hoya FCD100 ED glass
Lens cell: Machined aluminum
Aperture: 70mm
Focal length: 350 mm
F-ratio: f/5
Image circle: 43mm
Lens coatings: Fully multi-coated (all air-to-glass surfaces multi-layer coated)
Tube baffles: Multiple knife edge baffles
Tube length,dew shield fully retracted: 12.75" / 324mm
Weight: (with tube rings and dovetail bar attached) 8.5 lbs. / 3.9 kg
Tube rings: Split, felt lined, multiple threaded attachment holes
Focuser: Dual Speed (10:1), bias cut rack-and-pinion, rotatable
Focus knob shaft diameter: 6mm, with at side included
Drawtube travel: 29.5mm
Back focus 69.5mm (from the base of 48mm threads on 54-48mm adapter)
Rotatable focuser: Yes
Dew shield Retractable and lockable
Finder scope: Optional, dovetail nder scope shoe included
Dovetail mounting plate Vixen dovetail shape
Case: Hard case with custom cut foam interior

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.
Corporate Offices: 89 Hangar Way, Watsonville CA 95076 - USA
Toll Free USA & Canada: [phone]
International: [phone]
Customer Support: [email protected]
Copyright © 2022 Orion Telescopes & Binoculars.All Rights Reserved. No part of this product instruction or any of its contents
may be reproduced, copied, modied or adapted, without the prior written consent of Orion Telescopes & Binoculars.
AN EMPLOYEE-OWNED COMPANY