Vixen Great Polaris GP-DX User manual

"GREAT POLARIS"
"GP-DX"
EQUATORIAL MOUNT TELESCOPE
INSTRUCTION MANUAL

CONTENTS
"GREAT POLARIS" AND "GP-DX" EQUATORIAL
MOUNTS.3
FOR FIRST TIME TELESCOPE USERS . 4
] Step 1 | Proper assembly of the telescope.4
| Step 2 ] Installation of an eyepiece.4
1 Step 3 | First operation of the telescope 4
I Step 4 1 Your first look.5
Step 5 1 Changing eyepieces.7
1 Step 6^ Use of the finderscope . 7
Step 7 | Your first observation-the Moon! 8
| Step 8~~[ Observing Jupiter and Saturn.9
1 Step 9 Observing the Sun.g
| Step 10' General Cautions . 10
HOW TO SET UP THE EQUATORIAL MOUNT
TELESCOPE. i i
Roughly Aligning the Polor Axis of the Telescope 11
Using your Polor Axis Scope in the Northern Hemisphere 12
Using your Polor Axis Scope in the Southern Hemisphere 13
Aligning the Polor Axis Scope 13
HOW TO USE THE R.A. AND DECL. GRADUATION
RINGS (SETTING CIRCLES).15
HOW TO COLLIMATE THE OPTICAL SYSTEM OF A
NEWTONIAN REFLECTOR . 16
CAMERA ADAPTERS.17
MOTOR DRIVES . 18
PRECAUTIONS
Do not touch the lens or mirror with a
finger.
Do not drop or subject the telescope to
hard knocks.
Never wipe the lens or mirror with a hard
cloth. Use a soft silicone cloth or lens
cleaning tissue.
Never use the telescope in the water or in
Avoid setting up the telescope at a rough
NEVER LOOK DIRECTLY AT THE SUN WITH THE TELESCOPE. FINDERSCOPE
OR EYEPIECE. EYE DAMAGE AND OR DAMAGE TO THE INSTRUMENTS MAY
RESULT.
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"GREAT POLARIS" AND "GP-DX" EQUATORIAL MOUNTS
"GREAT POLARIS" Mount
'GP-DX" Mount
Safety Screw
Dovetail-Tube-Plate
Lock Screw
Decl. Clamp
Built-in Illuminator
Illuminator
R.A. damp
(opposite side)
Decl. Graduation Ring
R.A. Slow-Motion
Control Knob
Altitude
Graduation
Weight-Shaft
Lock Ring
Decl. Graduation Ring
Weight-Shaft ■ i
Lock Ring v# ,
R.A. Motor Cover
R.A. Motor Cover
Altitude Adjustment
Screw -— 40 _
Altitude Graduation Altitude Adjustment
Screw
Bubble Level
Bubble Level
W Azimuth Adjustmei
f Knob Azimuth Adjustmei
Knob
ide Adjustment
Cfttfnterweight
Counterweight
Counterweight Lock Screw Counterweight Lock Screw
Weight Shaft
Weight Shaft
Stopper
Stopper
Dovetail-Tube-Plate
Lock Screw
Safety Screw
r
(opposite side)
J R.A. Clamp
Decl. Clamp
((Specifications of "GREAT POLARIS"
Mount}) / ~ ”"7 c -
• R.A. and Decl. axes whole-circle micro-move¬
ment, 1 44-tooth worm gears
• R.A. graduation 10'increment
• Decl. graduation 2 increment
• R.A. slow-motion control knob attachable to
either side, 2.5 per revolution
• Decl. slow-motion control knob attachable to
either side, 2.5'per revolution
• Altitude adjustment 0 to 62 , about 2 per
revolution of adjustment screw
• Azimuth adjustment.±5 about 1 per revolution
of adjustment knob
• R.A. shaft maximum diameter 62mm
• Decl. shaft maximum diameter 62mm
• Weight shaft diameter 20mm
• Maximum loading weight about 7kg
Polar Alignment Graduations
R:A. Indicator
Graduatii
R.A. and Hod
Graduation Rii
Date
Graduation
Diopter Adjust]
Ring I
Polar Axis Scopl
Built-in Type Illuminator
Optional Batteries
■ ((Specifications of "GP-DX" Mount*
• R.A. and Decl. axes whole-circle micro-move¬
ment, 1 44-tooth worm gears
• R.A. graduation 10'increment
• R.A. and Decl. motor drives ±1,5x ±2x ±32x
• Altitude adjustment 0 to 62 ,about2 perrevo-
lution of adjustment screw
• Azimuth adjustment ±20 , about 1 per revolu¬
tion of adjustment knob
• R.A. shaft maximum diameter 62mm
• Decl. shaft maximum diameter 62mm
• Weight shaft diameter 20mm
• Maximum loading weight about 10kg
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FOR FIRST TIME TELESCOPE USERS
This manual will provide you with a better understanding of your new telescope —including its features, hardware and capabilities.
As with many things, the better you understand the workings of the equipment, the more enjoyment you will get from it.
This is particularly true of telescopes. So take a few moments now to become thoroughly acquainted with your new telescope.
Mastering an astronomical telescope is a key to the success in astronomical observation.
Step 1 Proper assembly of the telescope ' ■ . ,'
Pay particular attention to the following when assembling the telescope.
Make sure extension clamps that fix the tripod legs and a fixing knob for the mount on the underside of the tripod head are firmly
fastened. They provide the stability which is so important to quality observation.
Step 2 Installation of an eyepiece
©The magnification of your telescope is determined by the
eyepiece you use. It can be computed with the following
formula.
Magnification =
Focal Length of Obj ective ( mm)
Focal Length of Eyepiece (mm)
©Read the writing on the eyepiece, and you may find characters
such as "K20mm", "HMl2.5mm" or "LV5mm". The first letter
represents the type of eyepiece design, the number that follows
represents the focal length of the eyepiece. As the number gets
smaller, the magnification power of the eyepiece becomes
greater, thereby allowing the viewer to observe close-up detail.
©Eyepieces are classified into three sizes of barrel diameter,
24.5mm, 31 7mm and 50.8mm.
@To set a 24.5mm, 31.7mm or 50.8mm eyepiece, insert it in a
proper 24.5mm, 31.7mm or 50.8mm eyepiece adapter and
securely tighten the eyepiece setscrew.
Step 3 First operation of the telescope
©Unfasten the R. A. and Decl. clamps and you can move the
optical tube in a full range of motion.
CAUTION : DO NOT FORCE THE OPTICAL TUBE TO MOVE
WHEN THE R. A. CLAMP OR DECL. CLAMP IS
FULLY ENGAGED. THIS MAY DAMAGE
PRECISION PARTS OF THE MOUNT.
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To eliminate undue stress on the mount, the telescope should be properly balanced after all the standard accessories (i. e., star
diagonal, eyepiece, etc.) have been attached to the telescope. An unbalanced telescope may cause possible damage to the mount.
In addition, proper balancing is crucial for accurate tracking if using a motor drive.
®To balance the mount, release the R. A. clamp and position the
telescope off to one side of the mount. The counterweight bar
will extend horizontally to the opposite side of the mount.
Without tightening the R. A. clamp, gradually let go of the
telescope to see which way it rolls. Loosen the counterweight
and move it to a point where it balances the telescope.
Re-tighten the counterweight.
®The telescope should also be balanced on the declination axis
to prevent any sudden motions when the Decl. clamp is
released. To balance the telescope in Decl., release the R. A.
clamp and rotate the telescope so that it is on one side of the
mount (i. e., as described above for balancing the mount). Once
this is done, lock the R. A. clamp to hold the telescope in place.
Now, hold the telescope tube with one hand while releasing the
Decl. clamp with the other. The telescope will most likely rotate
around the declination axis. Slightly loosen the tube-ring screws
and slide the telescope either forward or backward in the tube
rings until it remains stationary when the Decl. clamp is released.
Re-tighten the tube-ring screws.
| Step 4 Your first look
Your first look should be done in the daytime when it will be easier to locate adjustment knobs and clamps.
This will help to familiarize you with your telescope, thus making it easier to use at night.
©Attach a low-power eyepiece having a long focal length. A
high-power eyepiece having a short focal length will make the
field of view darker and will make it more difficult to bring into
focus.
©Remove lens caps from the objective and eyepiece.
©Look through your telescope.
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@Try to find a clear object more than 200m away. Point the
telescope toward the object after unfastening both the R. A. and
Decl. clamps.
[Note] Eyepiece angle can be adjusted for your telescope by rotating
the optical tube in the tube rings after unfastening the tube-ring
screws.
©In the beginning, everything may blur. Gradually turn the focusing
knob until your object comes into sharp focus.
©Whoops! The view is upside down, and backward! But that's
OK —all astronomical telescopes operate this way as it really
doesn't matter in space. There are special prisms that correct the
condition, but they dim the image slightly.
r
How to use a Porro Prism or 45 Erect-lrhage Diagonal Prism))
To correct the upside-down view on the refractors, use a
36.4mm porro prism or 24.5mm 45 erect-image diagonal
prism fora 24.5mm eyepiece and a 31.7mm 45 erect-image
diagonal prism for a 31 . 7mm eyepiece.
[Note]
©The other porro prisms cannot be used for this purpose on
the refractors because these cannot close focus.
©Any prism cannot be used on Newtonian reflectors. 24.5mm
Eyepiece
Screw in.
36.4mm Porro Prism
Push in.
Adapter 36.4mn
,7mm
Eyepiece
131 [:7pihi 45 Erect-Image
Diagonal Prism.
IHow to use a Terrestrial Eyepiece))
Although the upside-down view can be corrected with a ter¬
restrial eyepiece, it makes the field of view narrow. Also, the
magnification power of the terrestrial eyepiece cannot be
changed. The method of calculating the magnification of the
terrestrial eyepiece is the same as those of other eyepieces.
[Note)The terrestrial eyepiece cannot be used on Newtonian
reflectors.
>= 3 >
Eyepiece Adapter
Push in.
m —
Insert Barrel
Terrestrial Eyepiece
(f = 18mm)
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Step 5 Changing eyepieces
©To remove the eyepiece, loosen the eyepiece setscrew and
slide the eyepiece out. Slide the chrome barrel of a
higher-power eyepiece into the eyepiece adapter and
re-tighten the setscrew to hold the eyepiece in place.
[Note]As the high-power eyepiece makes it more difficult to
bring into focus, turn the focusing knob slowly and carefully.
©The size of the image you now observe through the telescope
is larger.
Step 6 Use of the finderscope
How does a terrestrial view look through a finder ? Upside-down and backwards —just as through the main telescope. However, there
are points of slight difference.
(a) A crosshair reticle is seen. This is for pinpoint accuracy.
(b) A wider view is seen than when the main telescope is used.
The finderscope is simply to help you easily locate objects and bring them within the view of the main telescope. As your telescope —
even on "low" power—is still extremely powerful, finding the objects can be difficult. This is why telescopes are equipped with
finderscopes.
Prior to serious observations, make sure both the telescope and the finderscope are aligned—targeted on the same object. If the same
object is not centered in the crosshairs of the finderscope and centered in the main telescope, adjust the finderscope, using the position
setscrews.
{(Aligning the Finderscope!
©Attach a low-power eyepiece to the eyepiece adapter of your
telescope.
©Point the telescope at a clear object about 1 km away and center
it in the field of view.
©Bring the same object to the center of the crosshairs of the
finderscope, using the position setscrews.
({How to align the Finderscope);
© and @ show how to fasten the Position Setscrews
finderscope with the position set- (3pieces)
screws.
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(g)Put a low power eyepiece in the telescope. At low power (about
50 magnification), you will be able to see the entire lunar disk at
one time.
(NoteOOne of the best times to observe the Moon is during its partial
phases. Long shadows reveal a great amount of detail on the lunar
surface.
3 )If you later desire a close-up of a lunar region, use a higher power
eyepiece.
®Keep in mind that the rotation of the earth will cause the Moon
to drift out of the field of view. You will have to manually adjust
the telescope using the R. A. and Decl. slow-motion control knobs
to keep the Moon centered. This effect will be more noticeable at
higher power.
| Step 71 Your first observation—the Moon !
Now, you are ready to point the telescope toward celestial objects! Although observation may start with any celestial object, it is
advisable to start with the brightest objects first and work your way to fainter ones. Here is a good beginner s viewing order.
1. Moon 2. Jupiter 3. Saturn 4. Sun (with proper filter)
5. Venus 6. Mars 7. Mercury 8. Multiple Stars
9. Nebulae and Star Clusters
Now, let's look at the Moon.
®Locate the Moon in the finderscope and center it on the
crosshairs.
SHow to use a Moon Filter!
If you find that the lunar image is too bright for comfortable
viewing, attach a moon filter to the eyepiece. It will reduce the
brightness and, atthe same time, increase contrast on the lunar
surface.
How to use a Diagonal Prism!
A diagonal prism lets you view objects at a right-angle (90 ) from
the direction where the refractor telescope is pointing, thereby
allowing comfortable viewing when the telescope is pointed at
or near the zenith (directly overhead). Newtonian reflectors do
not require such a diagonal prism since objects are always viewed
from the side of the main tube of the telescope.
Eyepiece 9H CNote) The resulting image
BMI is right-side-up, but reversed
j=| left-to-right.
Diagonal Prism
1-Eyepiece Adapter
(Not usable on Newtonian reflectors)
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[ Step 81 Observing Jupiter and Saturn
Planets such as Jupiter and Saturn appear to steadily move across the sky from east to west. They appear as bright stars. Most
astronomy publications tell where the planets can be found in the sky each month.
©Use a low power eyepiece-about 50 magnification. Jupiter will
be seen like a small disk. You will also be able to see four moons
of Jupiter. (These satellites are not always visible because their
orbits carry them behind the planet.) Saturn, with its beautiful
rings, is easily visible.
©When seeing conditions are good (the atmosphere is steady),
raise the magnification greater than 100. You will be able to see
the cloud belts of Jupiter and the great Red Spot (if it is visible at
the time you are observing). The rings of Saturn and even the small
dark division (Cassini's Division) in the rings will be visible.
1 Ste p 9 Observing the Sun
CAUTION: NEVER POINT A TELESCOPE AT THE SUN AND NEVER LOOK DIRECTLY AT THE SUN WITHOUT TAKING ALL
PROPER PRECAUTIONS. READ THIS PARAGRAPH CAREFULLY BEFORE UNDERTAKING ANY SOLAR OBSERVATION.
All telescopes collect light—much more light than the human eye. Therefore, viewing the Sun through a telescope must only be undertaken
carefully, with all proper precautions observed. Fa ilure to take the proper preca uti ons may result in perma n ent blindness and dam age to
your teles cope. T o observe t he Sun safely, always f it the eyepiece w it h a sun filter. In a ddition, always place the obj ective cap on the
telescope with only the s mall solar aperture open . You will enjoy seeing sun spots—huge nuclear sun storms that constantly change position
and size.
/' t V / <, \ x y /
~Ser6w in.
Eyepiece
’Using the Sun Diagonal Prism
When the sun filter is used with the telescope for long observation, it may sometimes break from the heat. If a sun diagonal prism is added,
it exhausts 96% of sunlight and heat outside, so that only the remaining 4% of sunlight is used to observe the Sun, allowing long observation
with safety. A special sun filter to be screwed in the eyepiece belongs to the sun diagonal prism. Use the special sun filter together with
the sun diagonal prism. Its colour density is somewhat lighter than the ordinary sun filter. Only when using the sun dia g onal prism and
the special sun filter, take off the objective lens cap to expand the effective diameter of the objective lens and to enhance its resolving power.
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Step 10 General Cautions
(T)Try never to view through glass windows when observing. Clear as window glass seems, compared to the fine optical glass of
your telescope, it produces very distorted images. If the observation is undertaken through an open window, air movement
through the window (owing to the temperature difference between the inside and outside air) may cause image instability,
resulting in distortion.
(2)Be sure the optical axis of the telescope is centered. If the optical axis of the telescope is out of center, the image of an object
is lengthened or is unnecessarily coloured.
3)Stars other than the Sun can not be observed in an enlarged image, because they are very far from the earth as compared with
the Sun or other planets. However, your telescope can show you millions of stars not visible to the naked eye.
(DTrain your eye for observation. The figure of a celestial object observed through a telescope looks different depending upon the
experience of the observer. With repeated observation experience, you will begin to see objects that you could not earlier observe.
Sometimes averted vision-glancing slightly away from an object will help you see more detail.
©Stars appear to move very fast. Because a telescope tracks an object at high magnification for observation, the apparent
movement of an object seems rapid. For instance, when observing Jupiter at a magnification of 100, the moving planet takes
only about one minute and thirty seconds from the time when it first appears in the eyepiece to the time when it disappears.
We call this apparent motion because most of the motion is really the earth rotating under us !
((Newtonian Reflector
Primary-Mirror Cell
| Seco ndary-Mirror Support Arm a nd Adjustment Screws
The secondary mirror is of critical importance to the
proper operation of your telescope. Never turn the
adjustment screws except when you correct the
optical axis.
There are three pairs of
screws on the back of
the primary-mirror cell.
Never turn these screws
except when you cor¬
rect the optical axis.
When observing an object soon after taking the
telescope outside, you can sometimes see the
object appear to fluctuate. This is because warm
air and cold air are mixing in the tube. If possible,
expose the telescope to the open air for 20 to 30
minutes before observing, so that tube tempera¬
ture stabilizes.
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