Orion ShortTube 9386 User Manual

ShortTube™ 80mm
Refracting Telescope

#9386

Congratulations! Your new ShortTube™ 80mm Refractor is a
fine-quality instrument designed for both daytime terrestrial
viewing and nighttime stargazing. Compact, portable, and
easy to use, this versatile scope will provide many hours of
enjoyment for the whole family

WARNING: Never look directly at the Sun without

a proper, professionally made solar filter that fits
over the front of the telescope. Doing so could cause
permanent eye damage or even blindness.

Finder scope
alignment
screws

Finder scope
bracket

Focus lock
screw

Eyepiece

45° Diagonal

Parts List

Qty. Description

1 Optical tube assembly

2 1.25" eyepieces: 10mm Kellner and 25mm Kellner

1 45° correct-image diagonal, 1.25"

1 6x30 correct-image finder scope

1 Finder scope bracket and O-ring

1 Objective lens cap

Getting Started

The ShortTube 80mm comes nearly fully assembled from the fac tory.
Open the box and inspect the contents to make sure all of the parts
listed above are present. Please keep the original shipping container
in case you should need to ship the telescope back to Orion for war­ranty repair service. The box also makes a very good container for
storing the telescope when it is not in use.

The optics have been installed and collimated at the factory, so
you should not have to make any adjustments to them. To place
the finder scope in the finder scope bracket, first unthread the two
black nylon alignment screws until the screw ends are flush with the
inside diameter of the bracket. Place the O-ring that comes on the
base of the bracket over the body of the finder scope until it seats
into the slot on the middle of the finder scope. Slide the eyepiece
end (narrow end) of the finder scope into the end of the bracket’s
cylinder that does not have the alignment screws, while pulling the
spring-loaded tensioner on the bracket with your fingers. Push the

Rack­and-pinion
focuser

.

Finder scopeLock ring

Optical
tube

Dew cap/
lens shade

1/4"-20
Mounting

Focus
wheel

plate

finder scope through the bracket until the O-ring seats just inside the
front opening of the bracket’s cylinder. Now, release the tensioner
and tighten the alignment screws a couple of turns each to secure
the finder scope in place. Secure the bracket to the “dovetail” mount
on the optical tube with the knurled thumb screw provided. Insert
the 45° diagonal into the focuser tube and secure with the knurled
thumb screw. Slide an eyepiece into the diagonal and gently tighten
the thumb screw.

Mounting the Telescope on a Tripod

The ShortTube 80mm can be mounted on any standard camera tri­pod that has a 1/4"-20 stud. The stud threads into the small block
on the underside of the telescope’s optical tube. Alternatively, the
telescope can be attached to an equatorial mount equipped with a
1/4"-20 adapter. An equatorial mount is desirable for astronomical
viewing because it allows manual tracking of celestial objects as the
Earth rotates. Also, the setting circles on the mount enable you to
locate objects by their celestial coordinates (right ascension and
declination), which can be found in many books and star atlases.

Focusing

The ShortTube 80mm is equipped with a precision rack-and-pinion
focuser. When you first look in the eyepiece, the image you see may
be fuzzy, or out of focus. If so, gently turn one of the large focusing
wheels with your fingers until the image becomes sharp. You will
have to readjust the focus when aiming at subjects of varying dis­tances, or after changing eyepieces. Make sure the focus lock screw
is loosened before focusing. After focusing, you can tighten it to lock
the telescope’s focus into place.

If, when looking through the finder scope, you notice that the image
is fuzzy, you will need to focus the finder scope for your eyes. This
is done by first loosening the lock ring that is located behind the
finder’s objective lens cell. Once the lock ring is loosened, thread
the objective lens cell in or out until the image appears sharp. Then,
retighten the lock ring behind the lens cell. The finder scope is now
focused, and should not need focusing again for your eyes.

Aligning the Finder Scope

The ShortTube 80mm comes with a 6x30 finder scope. (The 6 means
six-times magnification, and the 30 indicates a 30mm- diameter front
lens.) Having a finder scope makes it easy to locate the subject you
want to observe with your telescope since it has a much wider field
of view. The finder scope and the telescope should be aligned so
that they both point to exactly the same spot.

Choose a tree, telephone pole, street sign—anything that is far off in
the distance, at least 200 yards away. Put that image in the center
of the field of your telescope’s eyepiece. Where is it in your finder
scope? Hopefully, the image will be in the field of view and some
simple adjustments of the two black nylon alignment screws on the
bracket will put the image dead center on the crosshairs. By loosen­ing or tightening the alignment screws, you can change the line of
sight of the finder scope. Continue making adjustments to the two
alignment screws until the image in both the finder scope and the
telescope’s eyepiece is exactly centered. Check the alignment by
moving the telescope to another object and centering it on the find­er’s crosshairs. Then look through the telescope’s eyepiece to see
if it is also centered in the telescope’s field of view. If it is, the job is
done. If not, make the necessary adjustments with the finder scope’s
alignment screws until the two images match up.

Finder scopes can come out of alignment during transport of the
telescope, so check the alignment before each observing session.

Providing Exceptional Consumer Optical Products Since 1975

Customer Support [phone]
E-mail: [e-mail]

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P.O. Box 1815, Santa Cruz, CA 95061

IN 068 Rev. B 0200

Terrestrial Viewing

The 45° diagonal provided with the ShortTube 80mm provides a
correctly oriented image. If, instead of the 45° diagonal, you use an
optional 90° “star diagonal,” which is preferred for astronomical use,
the view will be right-side up but backwards.

It’s best to start observing with the lower-power (25mm) eyepiece,
because it offers the wider field of view. With the eyepiece inserted
and secured in the 45° diagonal, simply point the telescope at the sub­ject you want to observe and center it on crosshairs of the finder scope
(which you’ve previously aligned with the main telescope, as explained
in the preceding section). Then look into the eyepiece and the subject
should be in the center of the field of view. If the view is blurry, adjust
the focus with the focus knob until the image appears sharp.

If you want higher magnification, switch to the 10mm eyepiece and
readjust the focus as necessary. Remember, increasing the magnifi­cation decreases the field of view and the image brightness.

Astronomical Viewing

When selecting a location for nighttime stargazing, make it as far
away from city lights as possible. Light-polluted skies greatly reduce
what can be seen with a telescope. A grass or dirt surface is prefer­able to asphalt, because asphalt radiates more heat, which disturbs
the air and compromises your view.

To find celestial objects with your telescope, you first need to become
reasonably familiar with the night sky. Unless you know how to rec­ognize the constellation Orion, for instance, you won’t have much
luck locating the Orion Nebula. A simple planisphere, or star wheel,
can be a valuable tool for learning the constellations and seeing
which ones are visible in the sky on a given night.

A good star chart or atlas can come in very handy for helping find
objects among the dizzying multitude of stars overhead. Except for
the Moon and the brighter planets, it’s pretty time-consuming and
frustrating to hunt for objects randomly, without knowing where to
look. You should have specific targets in mind before you begin
looking through the eyepiece.

The Moon, with its rocky, cratered surface, is one of the easiest and
most interesting subjects to observe with your telescope. The myriad
craters, rilles, and jagged mountain formations offer endless fasci­nation. The best time to observe the Moon is during a partial phase,
that is, when the Moon is not full. During partial phases shadows
cast by crater walls and mountain peaks along the border between
the dark and light portions of the lunar disk highlight the surface
relief. A full Moon is too bright and devoid of surface shadows to
yield a pleasing view.

Under dark skies, you can also observe a number of brighter deep­sky objects, including gaseous nebulas, open and globular star
clusters, and different types of galaxies. Most deep-sky objects are
very faint, so it is important that you find an observing site well away
from light pollution. Take plenty of time to let your eyes adjust to
the darkness. Don’t expect these subjects to appear like the photo­graphs you see in books and magazines; most will look like dim gray
smudges. (Our eyes are not sensitive enough to see color in deep­sky objects except in few of the brightest ones.) But as you become
more experienced and your observing skills get sharper, you will be
able to see more and more detail.

For astronomical observing, you may wish to replace the 45°
diagonal with an optional 90° star diagonal, which provides a more
comfortable viewing angle for observing objects overhead, and also
yields slightly better image resolution.

Photography with the ShortTube 80mm

With an optional camera adapter, the ShortTube 80mm becomes a
400mm f/5 telephoto lens for a single-lens reflex (SLR) camera. For
long-distance terrestrial or astronomical photography, you need only
a T-ring for your particular camera model. The T-ring screws onto

the threads on the ShortTube’s focuser drawtube, coupling the cam­era body to the telescope. For closer-range terrestrial photography,
you need both a T-ring for your camera and a T-Adapter (Orion item
#5264), which provides the extra focus travel needed.

Care & Maintenance

Give your telescope reasonable care and it will last a lifetime. 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.
If you wish, you can apply some white auto touch-up paint to the
scratch. Smudges on the tube can be wiped off with standard
household cleaners such as Windex or Formula 409.

Any quality optical lens cleaning tissue and optical lens cleaning fluid
specifically designed for multi-coated optics can be used to clean
the telescope’s objective lens as well as the lenses of the eyepiec­es and finder scope. Never use regular glass cleaner or cleaning
fluid designed for eyeglasses. Before cleaning with fluid 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 fluid to a tissue, never directly on the
optics. Wipe the lens gently in a circular motion, then remove any
excess fluid with a fresh lens tissue. Oily fingerprints and smudges
may be removed using this method. Use caution; rubbing too hard
may scratch the lens! On larger lenses, clean only a small area at a
time, using a fresh lens tissue on each area. Never reuse tissues.
Also, do not take eyepieces apart to clean them.

Specifications

Optical tube length: 15"

Objective lens: 80mm glass achromat

Focal length: 400mm

Focal ratio: f/5

Finder scope: 6x magnification, 30mm aperture, correctly oriented
image

Mount type: 1/4"-20 threaded receptacle

Eyepieces: 25mm (16x) and 10mm (40x) Kellner, 1.25"

Weight of optical tube assembly: 3 lbs., 7 oz.

One-Year Limited Warranty

Orion ShortTube 80mm™ is warranted against defects in
materials or workmanship for a period of one year from
the date of purchase. This warranty is for the benefit 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 to:
Orion Warranty Repair, 89 Hangar Way, Watsonville, CA

95076. Proof of purchase (such as a copy of the original
invoice) is required.

This warranty does not apply if, in Orion’s judgment, the
instrument has been abused, mishandled, or modified,
nor does it apply to normal wear and tear. This warranty
gives you specific legal rights, and you may also have
other rights, which vary from state to state. For further
warranty service information, contact: Customer Service
Department, Orion Telescopes & Binoculars, P. O. Box
1815, Santa Cruz, CA 95061; [phone].