Orion SHORTTUBE 80-T User Manual

INSTRUCTION MANUAL

Orion®

ShortTube

80mm Rich-Field Refracting Telescope

#9946

™

80-T

Providing Exceptional Consumer Optical Products Since 1975

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

Corporate Offices [phone]

89 Hangar Way, Watsonville, CA 95076

IN 121 Rev. D 02/09

Welcome to a new world of adventure! Your Orion ShortTube 80-T is a fine-quality instrument designed for both daytime ter-

restrial viewing and nighttime stargazing. Compact, portable, and easy to use, this versatile scope will provide many hours of
enjoyment for the whole family.

These instructions will help you set up and properly use and care for your telescope. Please read them over thoroughly before
getting started.

Finder scope bracket

Correct-image
finder scope

Dovetail
mount

Focus lock
thumb screw

Eyepiece

45° Correct­image
diagonal

Focus wheel

Figure 1. The Shor tTube 80-T refractor

WARNING: Never look at the sun with your telescope

(or even with just your eyes) without a professionally
made solar filter. Permanent eye damage or blindness
could result. Young children should use this telescope
only with adult supervision.

Avoid using the type of solar filter that screws into an
eyepiece. They are susceptible to cracking under the
intense heat that builds up near the focus point, and
could cause severe retinal damage. Use only the type of
solar filter that covers the front of the telescope. Be sure
also to cover the front of the finder scope with aluminum
foil or another opaque material to prevent physical dam­age to the internal components of the scope itself as well
as to your eyes.

Dew/glare
shield

Dovetail
mounting plate

Parts List

Qty. Description

1 Optical tube assembly

1 25mm Sirius Plössl 1.25" eyepiece (16x)

1 10mm Sirius Plössl 1.25" eyepiece (40x)

1 45° correct-image diagonal, 1.25"

1 6x26 correct-image finder scope

1 Soft carry case

1 Finder scope bracket with O-ring

1 Objective lens cap

2

Focus
lock-ring

Alignment thumbscrews

Tensioner

Figure 2a. The 6x26 correct-image finder scope and bracket.

Getting Started

The ShortTube 80-T comes nearly 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. Open the box and inspect the contents to make sure
all of the items in the parts list are present.

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.

Installing the Finder Scope

To place the finder scope in the finder scope bracket, first
unthread the two black nylon thumbscrews 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 opposite the adjustment screws while pulling the
chrome, spring-loaded tensioner on the bracket with your
fingers (Figure 2b.) Push the 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 two black nylon 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 thumb­screw provided.

Installing the Diagonal and Eyepiece

Insert the 45° diagonal into the focuser drawtube and secure
it with the knurled thumbscrew on the drawtube. Then insert
the 25mm Plössl eyepiece into the diagonal and secure it in
place with the thumbscrews on the diagonal. (Always loosen
the thumbscrews before rotating or removing the diagonal or
an eyepiece.)

Figure 2b.

bracket.

Mounting the Telescope

The ShortTube 80-T can be mounted on any standard camera
tripod that has a 1⁄4"-20 stud. The stud threads into one of the
threaded holes on the bottom of the dovetail mounting plate
attached to the underside of the telescope optical tube.

You can also easily mount the telescope on altazimuth tele­scope mounts like the Orion VersaGo. The dovetail mounting
plate on the bottom of the ShortTube 80-T connects to the
VersaGo mount’s dovetail holder. The dovetail holder has two
knobs to hold the dovetail mounting plate securely. Loosen
these two knobs accordingly and while grasping the telescope
firmly, place the dovetail mounting plate into the VersaGo's
dovetail holder. Tighten the two knobs to secure the telescope.

Alternatively, the telescope can be attached to any Orion
equatorial mount equipped with a dovetail holder. Follow the
directions above to couple the mounting plate to the equatorial
mount’s dovetail holder.

An equatorial mount is desirable for astronomical viewing
because it allows easy 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
observing books and star atlases.

Focusing

The ShortTube 80-T is equipped with a precision rack-and­pinion 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 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 thumbscrew is
loosened before focusing. After focusing, you can tighten it
to lock the telescope’s focus into place.

Inserting the finder scope into the finder scope

3