ORION TELESCOPES & BINOCULARS ED66-CF User manual

INSTRUCTION MANUAL
IN 595 Rev. A 10-17
Orion®ED66-CF 66mm Carbon
Fiber Refractor Telescope
Optical Tube Assembly
#40905
Congratulations on your purchase of the Orion ED66-CF Carbon Fiber refractor.Your telescope
has been designed with high quality precision optics and top-notch mechanical construction.
These instructions will help you set up and use your optical tube.
Please keep the original shipping box. In the unlikely event you need to ship the telescope back to Orion for war-
ranty 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.
Included Items
1 ED66-CF optical tube assembly
1 14mm wide-angle eyepiece
1 45-degree correct-image prism diagonal, 1.25"
1 Objective dust cover
1 Aluminum-clad carrying case
Refer to Figure 1 to familiarize yourself with the parts and features of the ED66-CF refractor.
Figure 1. The ED66-CF 66mm Carbon Fiber Refractor
Eyepiece
Focuser
Finder scope base Dew/glare shield
Diagonal
Mounting bar
Corporate Offices: 89 Hangar Way, Watsonville CA 95076 - USA
Toll Free USA & Canada: [phone]
International: [phone]
Customer Support: [email protected]
Copyright © 2020 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
The ED66-CF features a two-element 66mm-diameter objec-
tive lens, with one element made from FLP-51 “extra-low
dispersion” (ED) optical glass. Inclusion of this glass ele-
ment greatly minimizes chromatic aberration, or color fring-
ing, which is an inherent aberration in achromatic refractors.
The objective lens is “fully multi-coated,” which means that all
air-to-glass optical surfaces are multi-layer coated with anti-
reection material, to provide the highest possible light trans-
mission to the eyepiece.
About the Dual-Speed Crayford
Focuser
The ED66-CF comes equipped with a 1.25" dual-speed Crayford
focuser (Figure 2A). The Crayford design allows for smooth,
precise focusing without the image shift that rack-and-pinion
designs experience. Ten turns of the ne focus wheel on the
right side equals one turn of the coarse (rubber-grip) adjust-
ment wheel. Once you have achieved the best possible focus
on an object using the coarse adjustment wheel, you can ne-
tune your focus using the ne focus wheel to make micro adjust-
ments, to zero in on the precise focus point.
You can make adjustments to the focuser drawtube tension by
using the drawtube tension thumbscrew located on the bottom of
the focuser (Figure 2B). Turn this thumbscrew until the focuser
motion feels smooth and the drawtube does not slip once you
have obtained focus. If the thumbscrew is too tight the drawtube
will not move when the focus wheels are turned. It may be nec-
essary to make adjustments when the weight of your accesso-
ries changes signicantly. The focuser has 61mm of drawtube
travel.A convenient millimeter scale engraved on top of the draw-
tube lets you note the focus position and return to it quickly with
a given eyepiece and diagonal combination.
The focuser is fully rotatable. Just turn the knurled focuser rota-
tion collar (Figure 2A) counterclockwise to loosen the focuser
for rotation, then turn the collar clockwise again to secure the
focuser in the new orientation.
The telescope is equipped with a dovetail nder scope base,
which accepts any Orion nder scope as well as some other
brands. Using a nder scope, which offers low power and a wide
eld of view, makes it easier to pinpoint observing subjects and
center them in the main telescope’s eyepiece.
The focuser drawtube has an accessory collar (Figure 2A) that
accepts 1.25" accessories. For visual use you just slide the bar-
rel of the included 1.25" diagonal into the collar and then secure
it with the thumbscrew on the collar. The thumbscrew presses
against a compression ring inside the collar, which provides a
tight grip on the diagonal and prevents marring of the diagonal’s
barrel.
Attaching the Telescope to a Tripod
or Mount
The ED66-CF is equipped with a dovetail mounting bar (Figure
2B) that can be attached to a tripod or telescope mount. For
attachment to a telescope mount, make sure the mount has a
Vixen-style dovetail saddle. Simply insert the dovetail bar into the
saddle on the mount and tighten the saddle’s locking knob. For
attachment of the telescope to a photographic tripod, note that
on the underside of the telescope’s mounting bar are two ¼"-20
threaded holes. Either of these holes will accept the standard
1/4"-20 threaded post found on most photographic tripods.
Included Accessories
The ED66-CF comes with a 1.25" correct-image 45-degree prism
diagonal and a 14mm wide-eld eyepiece. The “correct-image”
diagonal has a barrel diameter of 1.25" and renders a normal
upright image. The 14mm eyepiece offers a wide 65-degree
apparent eld of view and 28.6x magnication (see below for
more on magnication).
Please note that the telescope will not come to focus without
the use of the diagonal or, if you prefer straight-through view-
ing, an optional extension tube. To install the diagonal, unthread
the thumbscrew on the accessory collar until it is ush with the
interior of the adapter. Insert the diagonal and secure it with the
thumbscrew. Then insert the eyepiece into the diagonal and
secure it with the thumbscrew on the diagonal.
Calculating Magnification (Power)
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
The ED66-CF has a focal length of 400mm. The eyepiece that
comes with it has a 14mm focal length. So the magnication is
28.6x:
400 ÷ 14 = 28.6x
It is desirable to have a range of eyepieces of different focal
lengths, to allow viewing over a range of magnications. So you
may eventually want to purchase additional 1.25" telescope eye-
pieces for more magnication options. For example, a 6mm eye-
piece would yield a magnication of 67x.
Every telescope has a useful limit of power of about 50x per
inch of aperture. So for the ED66-CF, which has an aperture of
66mm, or 2.6", that’s 130x. 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-pow-
er eyepiece to ferret out more detail, if atmospheric conditions
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,
over-magnied image.
WARNING: Never look directly at the Sun through
your telescope—even for an instant—without a
professionally made solar  lter that completely
covers the front of the instrument, or permanent
eye damage could result. Young children should
use this telescope only with adult supervision.

3
Extendable Dew/Glare Shield
Your telescope features an extendable dew/glare shield (Figure
1). Extend it prior to observing by pulling it forward until it clicks
to a stop. Extending the shield will inhibit dew formation on the
objective lens in moist conditions and will improve image con-
trast by blocking light from entering from the periphery to cause
unwanted glare.
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 in the foam-lined telescope
case (Figure 3) indoors or in a dry garage. Do not leave the tele-
scope outside when not using it. The optical tube is carbon ber
material underneath a protective “clear coat” surface. It is best to
clean the surface with a soft cotton towel and window cleaner. A
Figure 2. A) The 1.25” Dual Speed Crayford focuser in detail. B)
Underside of the focuser.
Figure 3. The ED66-CF and accessories in their aluminum-clad
carrying case.
Finder scope
base
Rotation collar
Fine focus wheel
Coarse focus
wheel
Dovetail
mounting bar
1/4"-20 holes
Drawtube
tension
thumbscrew
Accessory
collar
Millimeter
scale
paper towel may scratch the clear coat nish. If a scratch does
appear on the tube, it will not harm the telescope.
To clean the telescope’s objective lens as well as the lens of
the eyepiece, any quality optical lens tissue and cleaning uid
specically designed for multi-coated optics can be used. Never
use regular glass cleaner or cleaning uid designed for eye-
glasses. Before cleaning with uid and tissue, however, blow any
loose particles off the lens with a photographer’s 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; rub-
bing 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.
A
B

4
Specifications
Objective lens: Doublet, ED glass optics (S-FPL-51)
Objective lens diameter: 66mm
Focal length: 400mm
Focal ratio: f/6
Anti-reection coatings: Fully multi-coated (all air-to-glass surfaces multi-layer coated)
Tube material: Carbon ber and machined aluminum
Dew/glare shield: Carbon ber and machined aluminum, retractable
Focuser 1.25" dual-speed (10:1) Crayford, rotatable
Tube dimensions: 12" L x 5.75" W (with dew shield retracted)
Eyepiece: 5-element, 65-degree, fully anti-reection coated
Diagonal: 45-degree correct-image prism, 1.25"
Mounting: Vixen-style dovetail with two ¼"-20 holes in bottom
Finder scope: Dovetail base only (nder scope not included)
Weight: 4 lbs. 5 oz. (1.95kg)
Corporate Offices: 89 Hangar Way, Watsonville CA 95076 - USA
Toll Free USA & Canada: [phone]
International: [phone]
Customer Support: [email protected]
Copyright © 2020 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 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.