Orion ED80T CF User Manual

INSTRUCTION MANUAL

Orion® ED80T CF

Apochromatic Refractor

#9525

2" Diagonal

Dovetail base
for finder

Focuser rotation
lockscrew

Dew shield
(retracted)

2" Accessory
thumbscrew

Fine focus
knob

Course
focus
knob

Figure 1: The 80mm ED80T CF Apochromatic Refractor optical tube.

Focuser
rotation
lockscrew

1/4"-20
Mounting block

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

Corporate Offices [phone] • 89 Hangar Way, Watsonville, CA 95076

© 2008-2010 Orion Telescopes & Binoculars

IN 391 Rev. A 07/10

Congratulations on your purchase of an Orion
80mm f/6 Triplet Refractor. Your telescope has

been designed with high quality precision optics
and excellent mechanical construction. The dual­speed (11:1) Crayford focuser will make getting
sharp images a breeze and reduce image shift to
almost zero. The three element f/6 objective lens
offers excellent color correction. These instructions
will help you set up and use your optical tube.

Getting Started

The 80mm Triplet comes fully assembled from the factory. The
telescope’s optics have been assembled and collimated at
the factory, so you should not have to make any adjustments
to them.

Please keep the original shipping box. In the unlikely event
you 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.

Optical Use

The fine optics and precision machining make the 80mm
Triplet an excellent choice for astronomical and terrestrial
observation. You will need to attach the 2" diagonal (included)
and optional eyepiece to the back end of the telescope. The
telescope will accept 2" or 1.25" accessories. Simply slide the
diagonal into the open end of the telescope and insert the
eyepiece into the diagonal and it is ready to show you the
visual beauty of the night sky.

For terrestrial observation a correct image diagonal is recom­mended. These are typically available as 1.25" accessories
only.

Use of Optional Eyepieces, Diagonal, and
Finder Scope

The 80mm Triplet does not come with a finder scope or eye­pieces in order to grant the user the greatest versatility in cus­tomizing the instrument to suit their needs. However, certain
rules for using accessories still apply.

Any Orion finder scope with a dovetail bracket can be used
with 80mm Triplet. Simply unthread the thumbscrew on the
dovetail mount and insert the assembled finder scope and
dovetail bracket. Retighten the thumbscrew (Figure 1). Finder
scopes that do not use a dovetail bracket will need to be
attached by other means.

The 80mm Triplet can use 1.25" and 2" accessories. Please
note that the telescope will not come to focus without the use
of a diagonal or extension tube. To install a 1.25" diagonal,
unthread the thumbscrew on the 1.25" adapter until it is flush
with the interior of the adapter. 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).

Coarse

Focus lock
thumbscrew

Figure 2: Focuser detail

Use of 2" Eyepieces and Diagonals

A feature of the 80mm Triplet is its ability to also use 2" barrel­diameter eyepieces and diagonals. At low magnifications, 2"
eyepieces can give a wider field 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.

To use 2" eyepieces, simply loosen the large thumbscrew on
the 2" adapter (Figure 1). Once this thumbscrew is loosened,
the entire back end of the focuser, including any 1.25" diago­nal and eyepiece that may be attached, comes off, exposing
the 2" diameter focuser drawtube Now, insert your 2" diagonal
into the drawtube and secure with the two thumbscrews loos­ened previously. Insert a 2" eyepiece into the diagonal, secure
it in place with the thumbscrew on the diagonal, and you’re
ready to observe.

About the 2" Dual-Speed Crayford Focuser

The Triplet 80mm comes equipped with a 2" dual-speed
Crayford focuser. The Crayford design allows for smooth,
precise focusing without the image shift that rack-and-pinion
designs experience.

There is also a fine adjustment capability on this focuser.
Eleven turns of the small knob protruding from the right focus
knob equals one turn of the coarse adjustment knob. Once
you have achieved the best possible focus on an object using
the coarse adjustment knob; you can fine-tune your focus
using this slow motion knob to make micro adjustments. This
will allow delicate adjustments to be made to get the sharpest
images possible.

If you find that the focus adjustment is too hard to turn or does
not hold in place properly once you’ve achieved focus, you
can make adjustments to the focuser tension by using the fo-

focus knob

11:1 fine
focus knob

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cuser tension thumbscrew located on the bottom of the opti­cal tube, between the focus wheels. Make adjustments to this
thumbscrew until the focuser motion feels smooth to turn and
holds in place when you have obtained focus. It may be nec­essary to make adjustments when the weight of your acces­sories change significantly.

shaft of a sturdy camera tripod will thread into the hole on the
mounting block on the underside of the optical tube (Figure 1).

The tripod mounting block is also a dovetail bar designed to
attach to any Orion mount. Simply insert the dovetail bar into
the receiving dovetail cradle on the mount and tighten the
mounts attachment locking screws.

Photography with the
80mm Triplet

The Triplet 80mm f/6 refractor makes a very capable astro­graph for your CCD or DSLR camera. With an optional cam­era adapter, the Triplet 80mm becomes a 480mm f/6 tele­photo lens for a single-lens reflex camera. For long-distance
terrestrial or astronomical photography, you need a T-ring for
your particular camera model and a camera adapter. A 2"
prime focus camera adapter is suggested to obtain the best
focal distance for that optical tube. Simply attach the T-ring
to the camera body and thread the 2" prime focus camera
adapter into the T-ring. Insert the barrel of the camera adapter
into the 2" eyepiece holder on the focuser. Use the camera’s
viewfinder to frame the picture. Use the telescope’s focuser to
focus the image. Tighten the focuser tension thumbscrew to
make sure the camera does not slip out of focus.

Most CCD cameras will have a 1.25" or 2" barrel ready to
attach directly to your telescope like an eyepiece or diagonal.
No adapter is required, simply insert the barrel of the CCD
camera into the 1.25" or 2" eyepiece holder and secure the
camera with the silver thumbscrew lock.

The Triplet 80mm Refractors were designed to reach focus
with both DSLR and CCD cameras. However, every camera
focus point is a little different. Depending on your camera, you
may need to use an extension tube for your particular imag­ing setup. Any imaging accessory, such as a color filter wheel
increases the amount of inward focus travel required. Before
attaching any extra imaging accessory, try reaching focus first
with the camera directly attached to the focuser, then see if
you have enough focus travel left for extra accessories.

Imaging equipment is sometimes heavier than a diagonal
and eyepiece. The dual-speed Crayford focuser is capable of
handling the weight of your CCD or DSLR camera. Adding
tension to the focuser drawtube will increase the amount of
weight the focuser can handle. Install your camera onto the
2" or 1.25" adapter on the focuser during the day. Check the
focuser for any slippage. If the focuser drawtube slides under
the weight of the camera, you will need to add more tension
to the focuser.

You may want to consider using a remote shutter release
instead of the shutter release on the camera. Touching the
camera can vibrate the system and blur the resulting photo­graphic image. Also, be sure to use a solid tripod.

Attaching the 80mm Triplet f/6 to a Tripod
or Mount

The Triplet 80mm can be attached to a tripod or mount by the
use of the pre-installed 1/4"-20 mounting block. The 1/4"-20

Calculating Magnification (Power)

It is desirable to have a range of eyepieces of different focal
lengths, to allow viewing over a range of magnifications. To
calculate the magnification, or power, of a telescope, simply
divide the focal length of the telescope by the focal length of
the eyepiece:

Telescope Focal Length (mm)

Eyepiece Focal Length (mm)

For example, the 80mm, which has a focal length of 480mm,
used in combination with a 25mm eyepiece, yields a power of:

480mm

25mm

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 funda­mental law of optics). The steadiness of the air (the “seeing”)
will limit how much magnification 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 higher­power eyepiece to ferret out more detail, if atmospheric con­ditions permit. If the image you see is not crisp and steady,
reduce the magnification 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, overmagnified image.

= Magnification

= 19x

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 carbon fiber underneath a protective 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 household clean­ers such as Windex or Formula 409.

Any quality optical lens tissue and 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

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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! Clean only a small area at a time, using a fresh lens
tissue on each area. Never reuse tissues.

Specifications

Objective lens: Apochromatic triplet, air-spaced

Objective lens diameter: 80mm

Objective lens coatings: All air-to-glass surfaces coated,

with at least one surface
multi-coated

Focal length: 480mm

Focal ratio: f/6

Baffling: Internal baffles in tube and

focuser

Focuser: 2" dual-speed Crayford (with

1.25" adapter)

Tube diameter
(not including dew shield): 90mm

Tube length
(with dew shield retracted): 14.25"

Weight: 6 lbs.

One-Year Limited Warranty

The Orion 80mm f/6 Triplet Refractor 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 receipt) 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: Orion Customer Service [phone]; [e-mail].

Orion Telescopes & Binoculars

OrionTelescopes.com

89 Hangar Way, Watsonville CA 95076

Customer Support Help Line [phone] • Day or Evening

© 2008-2010 Orion Telescopes & Binoculars

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