Meade ETX-80AT-TC User Manual
Instruction Manual
ETX-80AT-TC
MEADE.COM
WARNING!
Never use a Meade®Telescope to look at
the Sun! Looking at or near the Sun will
cause instant and irreversible damage to
your eye. Eye damage is often painless, so
there is no warning to the observer that
damage has occurred until it is too late. Do
not point the telescope or its viewfinder at or
near the Sun. Do not look through the
telescope or its viewfinder as it is moving.
Children should always have adult
supervision while observing.
CAUTION: Use care to install batteries in
the orientation indicated by illustration in the
battery slots of the battery holder. Follow
battery manufacturer's precautions. Do not
install batteries backwards or mix new and
used batteries. Do not mix battery types. If
these precautions are not followed, batteries
may explode, catch fire, or leak. Improperly
installed batteries void your Meade warranty.
If you are anxious to use your telescope
for the first time, read the QUICK-START
GUIDE on page 4.
CONTENTS
Quick-Start Guide .......................................................... 4
elescope Features ...................................................... 6
T
AutoStar
Getting Started ..............................................................13
AutoStar Menus ............................................................20
AutoStar Operation ........................................................21
Advanced AutoStar Operation........................................28
Optional Accessor
Maintenance
Specifications ................................................................35
Appendix A: Using AutoStar to Enter Coordinates ........36
Appendix B:
Appendix C: Latitude Chart ............................................39
Appendix D: Training the Drive ......................................40
Appendix E: Basic Astronomy ........................................41
®
Features ........................................................10
Parts Listing ..............................................................13
elescope/Tripod Assembly ......................................13
T
Choosing an Ey
Manual Operation of the Telescope w/out AutoStar..14
Manual Operation of the Telescope with AutoStar....15
Slew Speeds ............................................................15
Observe the Moon ....................................................16
To Track an Object Automatically ..............................16
Moving Through AutoStar’s Menus ..........................16
Initializing AutoStar ..................................................16
Easy Alignment ........................................................18
Go To Saturn ............................................................18
Using the Guided Tour ..............................................19
Menu Tree ................................................................20
AutoStar Navigation Exercise ..................................21
Entering Data, Moving Through AutoStar’s Menus ..22
Objects Menu............................................................23
Event Menu ..............................................................24
Glossary Menu..........................................................24
Utilities Menu ............................................................24
Setup Menu ..............................................................25
Terrestrial Observing, Astronomical Observing ......28
Sidereal Rate ............................................................28
Advanced Alt/Az Alignment Methods........................28
Observing Satellites ..................................................29
Digital Photography with the ETX
Troubleshooting ........................................................34
epiece ..............................................14
®
............................30
ies......................................................32
..................................................................33
Polar Alignment..........................................37
The name
®
ks registered with the U.S. Trademark and Patent Office
mar
and in principal countries throughout the world. All rights
reser
Patents: US 6,392,799 and other patents pending.
© 2005 Meade Instruments Corporation.
“Meade
ed.
v
the Meade logo
”
,
, and
ade-
are tr
“ETX”
3
QUICK-START GUIDE
Step 1: Open tripod....and tighten lock ring.
Step 2: Loosen vertical lock to move optical
tube.
Setting up the Tripod
1. Open the tripod: Remove the tripod from the giftbox and
stand vertically. Gently pull the legs apart to a fully open
position. Turn the center tripod lock knob to secure and
stabilize the tripod. Tighten to a firm feel.
Caution: Make sure you loosen the tripod lock knob
before collapsing the tripod at the end of your
viewing session.
2. Loosen the vertical lock and move the optical tube downward. Then, re-tighten the vertical lock.
Attach the telescope to the tripod: Line up the
3.
mounting holes on the telescope with the mounting holes
on the base. Reach underneath and thread the mounting bolt through the tripod base and into the telescope
base. Tighten to a firm feel only, do not overtighten.
Note: If you wish to attach the accessory tray to the
tripod, see page 13 for more information. It is not
necessar
4. Insert the eyepiece: Remove the supplied 25mm eye-
piece from its container and slide it into the eyepiece
holder
Remove the dust cover from the end of optical tube
5.
assembly.
6. Use the focus knob to bring objects into focus.Your tel-
escope has a very precise focus control.You may need to
turn the focus knob 20 to 40 turns to focus your telescope
for the first time.
Always start observing using a low power eyepiece (such
as a 25mm or 26mm eyepiece) to get a nice wide field of
view. Later on you can change to high power, if so
desired. But high powered eyepieces have a much narrower field of view and it’s more difficult to locate objects
using high powered eyepieces.
y to attach the tray for the quick start procedure.
. Tighten the thumbscrews to a firm feel only.
Step 3: Attach telescope to tripod base using
mounting bolts
Steps 4 and 6: Insert eyepiece and focus
telescope.
.
Connect the AutoStar Handbox
7. Lift the battery cover. Gently remove the battery holder
from the compar
the wires attached to the holder. Insert 6 user-supplied
“AA” batteries in the holder. Refer to the diagram on the
holder to or
k into the batter
bac
8. Make sure that the computer control panel power switch
is in the OFF position. Remove AutoStar from the packing
materials and plug it into the HBX port.
Flip the Power Switch on the computer control panel to
the ON position. The copyright message lights on
utoStar’
A
9.
Press the key prompted by AutoStar to accept the Sun
warning.
s LCD displa
tment so y
ient the batteries properly. Replace the holder
y compar
ou don’t accidentally pull out
tment and replace the lid.
.
y
4
Step 7: Install batteries..
Step 8: Plug in handbox and turn on
computer control panel.
Observe
You can now use the AutoStar Arrow keys to move the telescope up, down, right, or left. To change the speed at which
the telescope moves (sometimes called the slew speed),
briefly press the Speed/? key. Each press decreases the
slew speed down one level, and then will cycle back to the
fastest speed.
Sight along the side of the telescope’s main tube to locate
an object. At first, practice during the daytime. Use the
AutoStar’s Arrow keys to center on objects in the telescope’s field of view. Observe trees, mountains, signs and
so forth. Then when you’re comfortable locating objects in
this manner, try observing at night on the Moon, planets
and stars.
Note about the Flip Barlow: To use the built-in flip Barlow,
rotate the the Flip Barlow control so that it is in the down
position (see diagram, left). The Flip Barlow doubles the
magnification of your eyepiece.
If you use the Flip Barlow, you will need to turn the focus
knob in a counterclockwise direction. You may have to turn
the focus knob 20 or more turns to focus with the Barlow
engaged.
Sight along the top of the optical tube.
lo
wn position.
Note: Flip Bar
tion.
Flip Bar
do
w control in the “down” posi-
lo
w in
5
TELESCOPE FEATURES
g
i
f
b
c
1@
1)
j
d
e
h
1$
1!
1&
1^
1#
1%
1. Eyepiece
2. Eyepiece holder thumbscrew
° Eyepiece holder
90
3.
4. Rear Cell Port
Flip mirror control (inset)
5.
6.
7. Battery compartment
8. Fork arms
9.
10. Objective lens cell
11. Base/Holes for tripod bolts
12. Dust cap
13. Vertical lock
14.
15. Focus knob
16. Computer control panel
17. Base housing
w
lo
Flip Bar
Optical tube
Horizontal lock
A. HBX port
B. LED
C. On/Off
D. AUX port
Fig. 1: The ETX-80AT Telescope.
6
A
B
C
D
1^
Fig. 1b : The computer control panel:
A - HBX port; B - LED; C - On/Off;
D - AUX port.
Fig. 1c: The battery compartment.
2)
2@
2#
1*
Fig. 2: The AutoStar
Handbox (see page 10).
h
1(
2!
Fig. 3: The tripod.
2%
2$
7
18.
AutoStar
19. Bubble level compass
ipod base
r
T
20.
21. Adjustable legs
22. Accessory tray
king knob
Loc
23.
24.
25. Leg locks
Leg br
aces
Caution:
Using products other
than standard Meade
accessories may cause
damage to the
telescope’s internal
electronics and may
void the Meade
warranty.
ETX: Your Personal Window to the Universe
The Meade ETX-80AT is an extremely versatile, high-resolution telescope with features similar
to those once available only with larger and more specialized imaging systems. With pushbutton controls, automatic tracking of celestial objects, and software downloading capability, an
ETX telescope may be all the telescope ever required by many terrestrial and astronomical
observers.
our ETX telescope reveals nature in an ever-expanding level of detail. Observe the feather
Y
structure of an eagle from 50 yards or study the rings of the planet Saturn from a distance of
800 million miles
clusters, remote galaxies, and even stars recently discovered to have planets orbiting about
them. Meade ETX telescopes are instruments fully capable of growing with your interest and
are ideal for both the casual observer and serious astronomer alike.
b Eyepiece:
tighten in place with thumbscrew (
. Focus beyond the Solar System and observe majestic nebulae, ancient star
Place the MA 25mm or other eyepiece into the 90° Eyepiece Holder (3, Fig. 1) and
2, Fig.1).
c Eyepiece Holder Thumbscrew: Secures the eyepiece. Tighten to a "firm feel" only.
° Eyepiece Holder:Holds the eyepiece upright for easy viewing.
d 90
E Rear Cell Port: Attach any 35mm camera with a removable lens to this port using an
optional #64ST T-Adapter.
F Flip Mirror Control: ETX telescopes include an internal mirror. With the flip mirror control
in the “Up” position, light is diverted to the eyepiece in the 90° eyepiece holder
3, Fig. 1). With the flip mirror control in the down position, light is diverted through the rear
(
cell port (
4, Fig. 1) for use with a camera for photography. See Figs. 4a and 4b.
Fig. 4a: Flip mirror
control in the “up”
position.
4b:
Fig.
control in the
position.
Flip mirror
wn”
“do
G Flip Barlow: Flip the switch to engage the Barlow. The Barlow doubles the magnification
of your eyepiece.You may have to turn the focus knob several times to refocus. See page
14 for more information.
H Battery Compartment: Install batteries in this compartment. See Step #7, page 13 for
more information.
I Fork Arms: Hold the optical tube in place.
J Optical Tube: The main optical component that gathers the light from distant objects and
brings this light to a focus at the eyepiece.
1) Mo
vable Objective Lens Cell:This component contains the telescope’s lenses.The focus
knob (
15,
Fig. 1
ves the cell for precise image focus.
) mo
1! Base/Bolt Hole for Tripod Bolts: Thread the tripod bolts up through the tripod
and into the two holes in the base.
1@ Dust Cap:
before observing.
Note: The dust cap should be replaced after each obser
power turned off to the telescope. Verify that any dew that might have collected during the observing session has evaporated before you replace the dust cap.
tical Loc
er
1# V
it to be freely mo
feel" only) prevents the telescope from being moved manually, but allows the vertical motor
drive to operate for AutoStar operation.
Caution: When loosening the v
(
9, Fig. 1). The weight of the objective lens could cause the tube to swing
suddenly downward and damage the telescope.
Unthread the dust cap counterclockwise from the front lens of the telescope
ving session and the
tical loc
k
ning the v
ur
T
:
ed up and down. Turning the vertical lock clockwise (tighten to a "firm
v
er
k counterclockwise unlocks the telescope, enabling
tical lock, be sure to hold onto the optical tube
er
1$ Horizontal Loc
izontal lock counterclockwise unlocks the telescope, allowing it to be freely rotated by
hor
hand side-to-side about the horizontal axis. Turning the horizontal lock clockwise prevents
the telescope from being rotated man
k:Controls the man
ual hor
, b
ually
ut allo
ws the hor
ontal motor dr
iz
ontal rotation of the telescope
iz
. Turning the
ive to operate
8
1% Focus Knob:
ocus an image. The ETX-80AT telescope can be focused on objects from a distance of
to f
about 17 ft. to infinity. Rotate the focus knob clockwise to focus on distant objects, and
countercloc
Note: The first time you focus the telescope, you may have to rotate the focus knob
20 to 40 complete turns as this is a fine focus mechanism which allows you to focus
an image very precisely.
Moves the telescope’s objective lens (10, Fig. 1) in a finely-controlled motion
kwise to focus on nearby objects.
1^ Computer Control Panel:
A. Handbox (HBX) Port
B. LED: The red power indicator light illuminates when power is supplied to
the AutoStar handbox and to the telescope’s motor drive.
C. ON/OFF Switch: Turns the Computer Control Panel and AutoStar ON or OFF.
D. Auxiliary (AUX) Port:
sories, such as the Meade “AstroFinder Software with Cable Connector Kit,” which
allows you to control your ETX from a PC. See
: Plug the AutoStar coil cord (8, Fig. 5) into this port.
Provides connection for current and future Meade acces-
OPTIONAL
ACCESSORIES
, page 32.
1& Base Housing: Contains mechanical and electrical assemblies that operate the telescope.
1* AutoStar with attached cord: See pages 10 to 12 for a description of AutoStar’s
features.
1( Bubble Level/Compass: Use when aligning your telescope. When the bubble is in the
center circle, the base is level.
The Tripod
2) Base: Attach the telescope to the base.
2! Adjustable Tripod legs: Support the telescope. The height of the legs can be adjusted.
2% below.
See
2@ Accessory tray: Place eyepieces and other accessories on the tray. Holds the AutoStar
handbox as well. Attach to one of the leg braces. See
2$ below.
2# Locking Knob: Rotate to secure the tripod legs. Be sure to loosen this knob before col-
lapsing the tripod.
2$ Leg Braces: Strengthens the tripod legs.
2% Leg Locks: Lift the lever to move the inner tripod leg segment in or out when adjusting the
height of the tr
ipod.
9
AUTOSTAR FEATURES
b
1 LCD Display
2 ENTER Key
3 MODE Key
4 GO TO Key
5 Arrow Keys
6 Scroll Keys
7 Speed/? Key
8 Coil Cord
c
e
d
f
g
h
Fig. 5: #494 AutoStar Handbox.
Tour the Cosmos with Just the Push of a Button
Control of the ETX-80AT is through the operation of the standard-equipment #494 AutoStar.
Nearly all functions of the telescope are accomplished with just a few pushes of AutoStar’s buttons. Some of the major features of AutoStar are:
• Automatically move the telescope to any of the 1400 objects stored in the database or
manually enter the astronomical coordinates of any celestial object.
• Take a guided tour of the best celestial objects to view on any given night of the year.
•
Download the latest satellite data and software revisions directly from the Meade website
.meade
www
(
al #506 AstroFinder
page 32.)
Access a glossar
•
• Calculate which eyepiece to use for optimum viewing of a celestial object.
Mount the telescope in the “Alt/Az” mode (Altitude - Azimuth, or vertical - horizontal) for
•
fully automatic tracking of celestial objects.
.com
) and share softw
Softw
™
y of astronomical ter
are with other A
are and Cab
ms
le Connector Kit. See
.
utoStar enthusiasts
OPTIONAL
i
(Requires option
.
CCESSORIES
A
-
10
utoStar Computer Controller provides control of virtually every telescope function within
The A
a compact handbox. AutoStar has soft-touch keys designed to have a positive feel. The LCD
(Liquid Cr
dark. The backlit display, key arrangement, and sequential database make AutoStar extremely
user friendly.
ystal Display) is backlit with a red LED (Light Emitting Diode) for easy viewing in the
Note: AutoStar does not require batteries; the telescope’s batteries supply power
to AutoStar.
b 2-Line LCD Display: Provides a visual interface between AutoStar and the telescope.
op line:
•
T
• Bottom line: Displays a menu option or information about a subject.
ys a menu item, or a menu option.
Displa
c ENTER Key: Accesses the AutoStar menus. See MOVING THROUGH AUTOSTAR'S MENUS,
page 16 and AUTOSTAR’S MENUS, page 20. The ENTER key is similar to the Return key
on a computer.
Note: If ENTER is pressed for two seconds or more and then released, AutoStar
emits a beep and “ENTER to Sync” is displayed. "ENTER to Sync" is relevant only
after the telescope has been aligned and is pointing at an object. If the "ENTER to
Sync" feature is accessed by mistake, press MODE to return to the previous
screen. See
HIGH PRECISION, page 27, for more details about this feature.
d MODE Key: Returns to the previous menu. If you keep pressing Mode, it will continue to
access previous menus until the top level, “Select Item," is reached. The MODE key is
similar to the ESCAPE key on a computer.
NOTE: If MODE is pressed and held for two seconds or more, the following information is then available using the Scroll keys (6 , Fig. 5):
• Right Ascension and Declination (astronomical) coordinates (see APPENDIX A)
• Altitude (vertical) and Azimuth (horizontal) coordinates
• Local Time and Local Sidereal Time (LST)
• Timer and Alarm Status
NOTE:
Throughout this manual, you will notice
the term "Alt/Az."
Alt/Az stands for altitude-azim
is just a fancy way of
saying the telescope
mo
and from side to side.
Not all telescopes
move like this. Alt/Az
alignment is just one
of many methods
used by amateur
astronomers to help
locate stars in the
night sky.
uth, which
ves up and down,
Press MODE again to return to the previous menu.
e GO TO Key: Moves the telescope to the coordinates of the currently selected object.While
the telescope is moving (or “slewing”), the operation may be stopped at any time by pressing any key except GO TO. Pressing GO TO again resumes the slew to the object.
f Arr
g Scr
ow Keys:Move the telescope up, down, left and right, at one of nine different speeds.
Speed selection is explained in
ys:
e
le with the Arro
ab
•
Alt/Az Alignment - Use the Up and Down Arrow keys to move the telescope vertically up and down. The Left Arrow key rotates the telescope (horizontally) countercloc
• Data Entry - Use the Up and Down Arrow keys to scroll through the letters of the
alphabet and n
the Up Arrow key starts with the digit "9." The Left and Right Arrow keys are used
to move the blinking cursor left and right across the LCD display.
ys
e
oll K
the first line of the screen.
second line
key to move quickly through the options.
The Scroll k
numerical digits.
:
TE
NO
alphabet & digits (A to Z, 0 to 9).
backward (Z to A, 9 to 0). Common symbols are also available in the list.
w k
, while the Right Arrow key rotates it clockwise.
kwise
umer
Accesses men
:
Press the Scroll keys to move through a list of options. Press and
.
ys, like the Arrow keys, also scroll through the letters of the alphabet and
e
The Scroll Do
SLEW SPEEDS, page 15. The following functions are avail-
The Down Arrow key starts with the letter "A" and
ical digits
wn k
.
u options within a selected men
Options within the men
y and the Do
e
The Scroll Up key and the Up Arrow key move
u are displa
wn Arrow key move forward through the
The men
u.
ed, one at a time, on the
y
u is displa
hold a Scroll
ed on
y
11
H Speed/? Key: Pressing the Speed/? key cycles through the nine slew speeds that move
TIPS
FOR BEGINNERS
the telescope. Each time the Speed/? key is pressed briefly, the current slew speed is
shown for about two seconds on the display. See
The Speed/? k
ey also accesses the "Help" file. "Help" provides on-screen information on
SLEW SPEEDS, page 15.
how to accomplish whatever task is currently active.
NOTE: Pressing the Speed/? key very briefly changes the slew speed. Holding
down the Speed/? key longer (one to two seconds) accesses the Help function.
Hold down the Speed/? key and then follow the prompts on the display to access details
of AutoStar functions in the Help feature. The Help system is essentially an on-screen
instruction manual.
If you have a question about an AutoStar operation,
e.g., INITIALIZATION, ALIGNMENT,
etc., hold down the Speed/? key and follow the directions that scroll on the second line of
the LCD screen. When a word appears in [brackets], press ENTER to access the AutoStar
Glossary. A definition or more detailed information is displayed. Press MODE to return to
the scrolling AutoStar Help display.
When satisfied with the Help pro
ue with the chosen procedure.
contin
vided, press MODE to return to the original screen and
I Coil Cord (not visible in diagram): Plug the AutoStar coil cord into the HBX port
A, Fig. 1) of the computer control panel of the telescope.
(
Join an Astronomy Club
Attend a Star Party
One of the fun ways to learn about astronomy is to
join an astronomy club. Check your local newspaper, school, library, or telescope dealer/store to find
out if there’s a club in your area.
At club meetings, you will meet other astronomy
enthusiasts with whom you will be able to share
your discoveries. Clubs are an excellent way to
learn more about observing the sky, to find out
where the best observing sites are, and to compare
notes about telescopes
and so forth.
Often, club members are excellent astrophotographers. Not only will you be able to see examples of
their art, but you may even be able to pick up some
ks of the trade” to try out on your ETX tele-
ic
“tr
See page 30 f
.
scope
photography with the ETX.
roups also hold regular
y g
Man
Parties at which you can check out and observe
with many different telescopes and other pieces of
astronomical equipment.
Telescope and Astronomy print schedules for many
popular Star Parties around the United States and
Canada.
y
, e
or more inf
Magazines such as
, filters
epieces
or
ly scheduled Star
ipods,
, tr
mation about
Sky &
12
Fig. 6a: Open the tripod...
Fig. 6b: ...turn the locking
ring to secure the tripod
legs.
Fig. 7: Unlock the vertical
lock and move the tube
down.
GETTING STARTED
Parts Listing
Getting the telescope ready for first observations requires only a few minutes. When first opening the packing box, note carefully the following parts:
• The ETX Astro Telescope with fork mount system, built-in flip barlow.
• #882 Standard Field Tripod with carry case
Accessory tray with mounting bolts and wingnuts
•
• #494 AutoStar handbox with attached coil cord.
• Meade premium eyepieces.
• Hex-wrench, packed with the instruction manual. See
page 33.
Telescope Assembly
Setting up the Tripod
1. Open the tripod: Remove the tripod from the giftbox and stand vertically. Gently pull the
legs apart to a fully open position. See
Fig. 6a. Turn the center tripod lock knob to secure
and stabilize the tripod. See Fig. 6b. Tighten to a firm feel.
Caution: Make sure you loosen the tripod lock knob before collapsing the tripod at
the end of your viewing session.
2. Loosen the vertical lock and move the optical tube downward.Then, re-tighten the vertical lock. See
Fig. 7.
3. Attach the telescope to the tripod: Line up the mounting holes on the telescope with the
mounting holes on the base. Reach underneath and thread the mounting bolt through the
tripod base and into the telescope base. See
Fig. 8.Tighten to a firm feel only, do not over-
tighten.
4. Attach the tray to the tripod: Line up the mounting holes on the accessory tray with the
mounting holes on one of the tray struts. See
Fig. 9. Remove the wingnuts from the two
mounting bolts. Slide the mounting bolts through the top of the tray and through the tray
struts. Reach underneath the tray and thread the wingnuts back onto the bolts. Tighten to
a firm feel only.
Insert the eyepiece: Remove the supplied 25mm eyepiece from its container and slide it
5.
into the eyepiece holder
. See Fig. 10. Tighten the thumbscrews to a firm feel only.
6. Remove the dust cover (12, Fig. 1) from the end of optical tube assembly.
Connect the AutoStar Handbox
7. Remove the battery compartment:
Lift the battery cover. Gently remove the battery holder from the compartment so you don’t accidentally pull out the wires attached to the holder. Insert 6 user-supplied “AB” batteries in the holder. Refer to the diagram on the holder
to orient the batteries properly. Replace the holder back into the battery compartment and
replace the lid.
See
Fig.
11a
.
GENERAL MAINTENANCE
Fig. 8a: Thread bolts
through the telescope base
Fig. 9: Attach accessory
tray to leg braces using
supplied bolts and
wingnuts.
.
Fig. 10: Insert eyepiece and
focus.
Fig. 11a: Install batteries.
11b:
Fig.
and tur
Connect the A
n on the computer control panel.
utoStar handbo
x
13
Plug in the handbox:
8.
OFF position. Remove AutoStar from the packing materials and plug it into the HBX port.
Flip the Power Switch on the computer control panel to the ON position. The copyright
message lights on AutoStar’s LCD display. See
9. Accept the Sun Warning:
e sure that the computer control panel power switch is in the
Mak
Fig. 11b.
Press the key prompted by AutoStar to accept the Sun warning.
Choosing an Eyepiece
A telescope’s eyepiece magnifies the image formed by the telescope’s main optics. Each eyepiece has a focal length, expressed in millimeters, or “mm.” The smaller the focal length, the
higher the magnification. For example, an eyepiece with a focal length of 9mm has a higher
magnification than an eyepiece with a focal length of 25mm.
our telescope comes supplied with two standard eyepieces.
Y
Low power eyepieces offer a wide field of view, bright, high-contrast images, and excellent eye
relief during long observing sessions. To find an object with a telescope, always start with a low
power eyepiece. When the object is located and centered in the eyepiece, you may wish to
switch to a higher power eyepiece to enlarge the image as much as practical for prevailing seeing conditions.
Note: Seeing conditions vary widely from night-to-night and site-to-site. Turbulence
in the air, even on an apparently clear night, can distort images. If an image
appears fuzzy and ill-defined, back off to a lower power eyepiece for a more wellresolved image (
The power, or magnification of a telescope is determined by the focal length of the telescope
and the focal length of the eyepiece being used. To calculate eyepiece power, divide the telescope's focal length by the eyepiece's focal length.
piece. The focal length of the ETX-80AT is 400mm (see SPECIFICATIONS, page 35).
Telescope Focal Length ÷ Eyepiece Focal Length = Magnification
The eyepiece power, or magnification is therefore 14x. However, your telescope also contains
a built-in 2 times Barlow. This means you also have to multiply magnification figure by two.
Fig. 14a and 14b, page 17).
E.g., Assume you are using a 25mm eye-
400mm ÷ 25mm = 16
Fig. 12: To use Flip
Barlow, rotate the flip
control to the “down”
position.
16 x 2 = 32
So your telescope has a 32 times magnification.
Manual Operation of the Telescope without AutoStar
If you wish to observe a distant land object, such as a mountain top or a bird, you can observe
by merely pointing the telescope and looking through the eyepiece. Assemble the telescope,
loosen the horizontal and vertical locks (
object you wish to observe. Sight along the top of the tube until you find the object. When the
object appears in the eyepiece, focus the image using the by turning the focus knob (
1). Rotate the knob clockwise to focus on distant objects and counterclockwise to focus on
nearby objects.
You can also observe stars and objects in the night sky using this method, but note that objects
begin to slowly drift across the eyepiece field.This motion is caused by the rotation of the Earth.
Fig.13:
the optical tube.
Sight along the top of
13 and 14, Fig. 1), and turn the telescope towards the
15, Fig.
As you become familiar with AutoStar operation, you can
counteract the drift using the automatic tracking feature in
the Setup menu (see
LY , page 16), or by using AutoStar's GO TO capabilities (see
GO TO SATURN, page 18).
Sight along the top of the telescope’s tube to line up objects
f
or viewing in the eyepiece. See
TO TRACK AN OBJECT AUTOMATICAL-
Fig.
13.
14
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