Orion EON 10287 User manual

Orion®EON 80mm ED
Apochromatic Doublet
Refractor
#10287
IN 662 6/21
INSTRUCTION MANUAL
Corporate Offices: 89 Hangar Way, Watsonville CA 95076 - USA
Toll Free USA & Canada: [phone]
International: [phone]
Customer Support: [email protected]
Copyright © 2021 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
Congratulations on your purchase of the Orion EON 80 ED Apochromatic Refractor optical tube.
Your 80mm f/7 ED has been designed with high quality optics and excellent mechanical construc-
tion. The ED glass in the objective lens means you’ll enjoy images with far less color distortion
than those seen in a standard refractor, and the smooth and robust dual speed Rack and Pinion
focuser will make getting sharp images a breeze. These instructions will help you set up and use
your telescope tube.

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WARNING: Do NOT look at the Sun without a
professionally made solar filter on the telescope;
serious eye damage may result if you look at the
Sun with any unfiltered optical instrument. Do not
leave the telescope unsupervised around children.
Always cover the lenses when leaving the telescope
in direct sunlight.
Figure 1. The EON 80 ED Apochromatic Refractor optical tube assembly
Dew shield locking
setscrews (3x)
Fine focus knob
Coarse focus knob
2" accessory
collar
Dovetail nder
base
Tube rings
Retractable dew shield
Objective lens cover
1.25" adapter
Getting Started
The EON 80mm ED comes fully assembled from the factory.
The telescope’s optics have been installed and collimated, so
you should not have to make any adjustments to them.
Please keep the original shipping box! In the unlikely event you
should need to ship the telescope back to Orion for warranty
repair service, you should use the original packaging. The box
also makes a very good container for storing the telescope
when it is not in use.
Attaching the EON 80mm ED to a Tripod or Mount
The EON 80mm ED can be attached to a tripod or mount by
the use of the narrow Vixen style dovetail rail. This dovetail
ts any mount capable of connecting a Vixen style dovetail,
including the Orion AstroView, SkyView Pro, Sirius, and Atlas
mounts. In addition, in the middle of the dovetail plate is a
threaded ¼"-20 hole designed for any standard photo tripod,
so the EON can be connected to any camera tripod capable of
holding the weight of the optical tube.
Machined felt-lined rings are included with your EON, and
come fully assembled and connecting in the box. In addition,
on the top of those tube rings are a series of 6mm (1mm per
thread) mounting holes, designed to connect any auxiliary rail
or other accessory to the top of your telescope.
Use of Optional Eyepieces, Diagonal, and Finder
Scope
The EON 80mm ED does not come with a nder scope, diago-
nal or eyepieces in order to grant the user the greatest versatil-
ity in customizing the instrument to suit their tastes. However,
certain rules for using accessories still apply.
Any Orion nder scope with a dovetail bracket can be used
with the EON 80mm ED. Simply unthread the thumbscrews
on the dovetail mount (Figure 1) and insert the assembled
nder scope and dovetail bracket. Retighten the thumbscrews.
Finder scopes that do not use a dovetail bracket will need to be
attached by other means.
The EON 80mm ED can use almost any 1.25" diagonal or eye-
piece. Please note that the telescope will not come to focus
without the use of a diagonal or extension tube. To install a
diagonal, loosen the thumbscrew on the 1.25" adapter (Figure
1). Insert the diagonal or extension tube and secure it with
the thumbscrew. Then insert the eyepiece into the diagonal or
extension tube and secure it with the thumbscrew(s).
Use of 2" Eyepieces and Diagonals
A feature of the EON 80mm ED is its ability to also use 2" bar-
rel-diameter eyepieces and diagonals. At low magnications,
2" eyepieces can give a wider eld of view than standard 1.25"
eyepieces. This is especially desirable for observing deep-sky
objects, as many of them appear quite large, but faint. As with
1.25" eyepieces, the EON 80mm ED will not reach focus with
the 2" eyepieces unless a 2" diagonal or extension tube is
used.
To use 2" eyepieces, simply loosen the three large thumb-
screws on the 2" adapter (Figure 1). Once these thumbscrews
are loosened, the entire back end of the focuser, including
any 1.25" diagonal and eyepiece that may be attached, comes

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Figure 2. The Rack and Pinion Focuser adjustments
Focus tension setscrew
Focus lock
thumb knob
off, exposing the 2" diameter focuser drawtube. Now, insert
your 2" diagonal into the drawtube and secure with the three
thumbscrews loosened previously. Insert a 2" eyepiece into the
diagonal, secure it in place with the thumbscrew on the diago-
nal, and you’re ready to observe. The EON 80 focuser features
brass compression rings to securely hold your eyepieces and
diagonal in place without marring the 1.25" or 2" nosepiece
walls.
2" Rack and Pinion Focuser
The EON 80mm ED comes equipped with a solid 2" dual
speed Rack and Pinion (R&P) focuser. The R&P design allows
for smooth, precise focusing without any slippage that typical
Crayford focuser designs can experience. And backlash has
been minimized by using a large Rack gear cut on a diago-
nal bias to fully mesh the Pinion gear at all times. The focuser
includes a 10:1 reduction gear for super precise focusing. The
black knobs are the course focus, and the gold knob is the ne
focus. For every one full turn of the course knob, the ne knob
will turn 10 times.
A focus lock thumb knob is located on the Pinion housing
between the two focus knobs (Figure 2). Leave this knob fully
unlocked during normal operation, and only lock it when you
do not want the focus to change at all. Under normal operation
the focus should not move on its own, even with this lock knob
fully disengaged. But if you load the focuser with very heavy
gear, you might nd the factory tension is not strong enough to
hold against gravity and the wheels may begin to turn on their
own when aiming at high altitudes. If this happens, slightly
tighten the focus tension setscrew (Figure 2) a small amount,
and retest for holding strength. This setscrew should only be
tightened enough to hold the weight of your equipment.
Retractable Dew Shield
The front dew shield (Figure 1) is retractable to allow for easy
transport and storage, and pulls out to full length to provide
protection from dew and stray light from sources such as near-
by streetlights or buildings. The dew shield should hold secure-
ly in position on its own, but if you nd it slipping during use,
there are three allen head set screws around the perimeter of
the bottom ring of the dew shield (Figure 2). Use a 2mm Allen
wrench to gently tighten down these three setscrews, and the
dew shield will stay securely in place. It’s best to slightly loosen
them again when you wish to retract the dew shield.
Calculating Magnification (Power)
It is desirable to have a range of eyepieces of different focal
lengths, to allow viewing over a range of magnications. 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:
Telescope F.L. ÷ Eyepiece F.L. = Magnication
For example, the EON 80mm ED, which has a focal length of
560mm, used in combination with a 25mm eyepiece, yields a
power of
560 ÷ 25 = 22.4x.
Every telescope has a useful limit of power of about 50x per
inch of aperture. Claims of higher power by some telescope
manufacturers are a misleading advertising gimmick and
should be dismissed. Keep in mind that at higher powers, an
image will always be dimmer and less sharp (this is a funda-
mental law of optics). The steadiness of the air (the “seeing”)
will limit how much magnication an image can tolerate.
Always start viewing with your lowest-power (longest focal
length) eyepiece in the telescope. After you have located and
looked at 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, overmagnied image.
Note About Chromatic Aberration
Chromatic aberration literally means color distortion.Whenever
light passes through one material to another, light of different
wavelengths (color) is 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 unacceptable images.
The EON 80mm ED is designed to minimize chromatic aberra-
tion. The objective lens is actually comprised of two individual
lenses, called elements, one of which is made of special ED
(Extra-low Dispersion) glass, a special type of glass that has
superior refractive properties when compared to normal types
of glass. The use of this ED glass coupled with the proper mat-
ing lens minimizes the amount of chromatic aberration, result-
ing in a much more pleasing view when compared to tele-
scopes that do not use ED glass.
Photography with the EON 80mm ED
With optional camera adapters, the EON 80mm ED becomes
a 560mm f/7 telephoto lens for DSLR and dedicated astro
cameras. For long-distance terrestrial or astronomical pho-
tography with a DSLR, you need a T-ring for your particular
camera model along with a 2" prime focus camera adapter or
dedicated eld attener or reducer. Please note: If you use a
eld attener such as the Orion #8893, or the focal reducer

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(#8894), you will most likely not need any extension tubes to
reach focus. But if you choose to use the telescope without
a attener or reducer, it’s likely that you will also need a 2"
extension tube to reach focus with a DSLR or dedicated astro
camera.
If you wish to use a 3rd party robotic focus motor for automat-
ed focus, use the threaded hole for the focus lock thumbscrew
(Figure 2) to secure the motor bracket. The lock knob is not
normally used when a robotic focuser is attached and can be
removed. Please make sure to nd a screw that is only long
enough to engage the threads and tighten down the bracket
– it needs to be short enough to NOT begin to lock down the
focus mechanism internally. Use washers if necessary to hold
the screw higher and away from locking down the focuser. The
focus lock knob threaded hole is M4 x 0.7mm
Care & Maintenance
Give your telescope reasonable care and it will last a lifetime.
When not in use, keep its dust cover on as well as the dust cap
on the eyepiece opening. Store it indoors or in a dry garage.
Do not leave the telescope outside except when using it. The
optical tube is aluminum and has a smooth painted surface
that should resist scratches and smudges. If a scratch does
appear on the tube, it will not harm the telescope. Smudges
on the tube can be wiped off with standard mild household
cleaners.
Any quality optical lens tissue and cleaning uid specically
designed for multi-coated optics can be used to clean the tele-
scope’s objective lens as well as the lenses of the 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 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.
Specifications
Optical tube: Seamless aluminum
Objective lens diameter: 80mm (3.1")
Objective lens: Apochromatic doublet, rear element made of Fk-61 ED glass, air-spaced
Objective lens coating: Fully multi-coated (all air-to-glass surfaces multi-layer coated)
Lens cell: Machined aluminum
Focal length: 560mm
Focal ratio: 7.0
Focuser: Rack and Pinion, 10:1 dual speed, compression locking, 2" w/ 1.25" adapter
Back focus: 153mm
Mounting bar: Vixen dovetail rail with slots and included ¼"-20 tripod threaded hole
Tube rings: Two hinged, felt lined rings, multiple M6-1.0 holes included
Weight: 5 lbs. 13 oz.
Length: 17.25"
Corporate Offices: 89 Hangar Way, Watsonville CA 95076 - USA
Toll Free USA & Canada: [phone]
International: [phone]
Customer Support: [email protected]
Copyright © 2021 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
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 warranty period Orion Telescopes & Binoculars will
repair or replace, at Orion’s option, any warranted instrument 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.