National Geographic NG55CS Quick start guide

NG55CS
Maksutov-Cassegrain
Telescope
Instructions
and
Owner’s Manual
Manual Part #: 264966

Introduction
Congratulations on your purchase of a precision-crafted NATIONAL GEOGRAPHIC™
telescope. With proper care and handling of your telescope, you will enjoy the pleasure
of looking at nature’s wondrous sights through the eye of this instrument for many
years.
Your new Maksutov-Cassegrain telescope provides you with the clarity and contrast of
a lens type (refractor) telescope and the brightness and color fidelity of a mirror type
(reflector) telescope. And it all comes in an easy-to-use, compact package.
As a terrestrial (land) telescope, the NG55CS delivers great views of mountains,
valleys, wildlife, and many other wonders and features of the world around us. Its
compact size and light weight make it an ideal telescope for hikers, travelers, cottagers,
and anyone else who demands superior optical performance in a small telescope.
As an astronomical telescope your NG55CS will reward you with excellent views of
lunar detail, Jupiter’s four largest “Galilean” moons, and even Saturn’s rings.
To obtain the best performance from your telescope, please read this manual carefully
and completely.
WARNING!
CHOKING HAZARD
Small parts. Not suitable for
children under 3 years.
!
WARNING!
NEVER aim your telescope at the sun or even close to the sun!
Instant and irreversible damage can occur,
including blindness!
Do not let children use any telescope without adult supervision.
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SETUP:
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1) Position the telescope and the tripod so that the ¼” x 20 tripod bolt is aligned with
the tripod socket underneath the telescope tube (1). Hand-tighten the tripod bolt
by turning it clockwise. Do not over-tighten.
2) Spread the three tripod legs and set the unit down on a level surface.
3) You can adjust the height of the telescope by loosening the ring (2) around the
center column of the tripod and moving the telescope up and down. When the
telescope is in the proper position re-tighten the ring.
4) To make small directional changes there are two micrometric adjustments. The
vertical adjustment (3) is located at the rear of the tripod head and the lateral
(side-to-side) adjustment (4) is located on the side of the tripod head.
Note: Because these are fine motion adjustments they have limited movement
ranges. If you cannot turn an adjustment knob, do not force it. You have reached the
limit of the adjustment. You must turn the knob in the opposite direction 4 or 5 times.
Then re-position the tripod to aim the telescope at the subject being observed. You
will find that you have regained fine motion adjustment.
5) To make a large vertical adjustment, loosen the large knob (5), adjust the
telescope, and then re-tighten the large knob.
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ZOOM and FOCUS:
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1) Your telescope is equipped with a 30X-90X zoom eyepiece* (6). To change the
magnification power, gently turn the rubber zoom ring (7) on the eyepiece. The
magnification power is indicated on the side of the eyepiece.
* Some models may be equipped with zoom eyepieces with a 15X-45X power
range or a 20X-60X power range.
2) Set the eyepiece to its lowest magnification.
3) Turn the rubberized focusing knob (8) until you see the clearest image. The focus
adjustment actually moves the rear mirror inside your telescope. This precision
adjustment gives you the ability to make extremely fine focus adjustments.
4) To see your subject at a higher magnification, turn the zoom ring (7) on the
eyepiece. You will have to re-adjust the focusing knob (8).
5) Note that as the zoom power increases, the brightness of the image decreases.
This is quite normal. To observe in low light situations you will find the lower
zoom powers perform better.
USING YOUR TELESCOPE FOR ASTRONOMICAL VIEWING
1) Take your telescope outside. We do not recommend viewing objects through a
window. Your view can be distorted by reflections in the glass of a closed window or
by air currents of differing temperatures passing through an open window.
2) Allow your telescope to adjust to the outside temperature. Your telescope will
perform much better if the temperature of the lenses and the air inside the tube are
the same as the outside temperature. We recommend that you allow 30 minutes to
equalize the temperatures when the difference in temperature difference is extreme.
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If you try to use the telescope before it has adjusted to the outdoor temperature you
may find it somewhat difficult to focus accurately.
3) Find a location away from any direct light source. If you live in a large town or city,
your viewing will probably improve the farther you move away from the ‘light
pollution’ of city lights. The sky glow of a town or city can dramatically reduce the
telescope’s performance and viewing capabilities.
4) Remove the round plastic dust cover (lens cap) from the front of your telescope.
5) We strongly recommend that you begin your viewing session with the 30X zoom
power. It will give you the widest angle and the brightest, sharpest view.
When possible, avoid sudden temperature changes, as the moisture in the air may
condense as water droplets (dew) on the objective lens. If dew forms on your objective
lens do not wipe it off. Take your telescope indoors and follow Step 2 – below on this
page.
CARE AND CLEANING OF OPTICS
Optical components of a telescope get dirty over time. Dirt or dust on a lens should be
removed with the utmost care. A considerable amount of dirt or dust would have to
accumulate on the optical surface before your view would be compromised.
1) Keeping the dust cap on during storage and transport and keeping the telescope in
its case will reduce dust collection.
2) Condensation may collect on the optical surfaces when the telescope is not in use.
Remove the dust cap and allow the moisture to evaporate naturally. Point the telescope
downward to minimize the accumulation of airborne dust.
3) Once all moisture has evaporated, replace the dust cap.
3) Filtered, compressed air may be used to remove surface dust from lenses and
mirrors. Remove the dust cap. Once removed, point the can away from the lens and
gently expel some air and any condensation or dust that has accumulated on the
discharge tube. Spray the lens with short bursts of air to carefully remove the dust
particles. DO NOT HOLD THE TRIGGER OF THE COMPRESSED AIR CAN FOR
EXTENDED PERIODS BECAUSE PROPELLANT FROM THE CAN MIGHT
ESCAPE AND DAMAGE THE OPTICAL SURFACE.
If, after several attempts, you cannot remove the particles, take the telescope to an
optical professional for cleaning.
If you keep the dust cap on your telescope when it is not in use and avoid handling the
lenses, only minimal optical maintenance of your telescope should be required.
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WHAT TO LOOK FOR IN THE NIGHT SKY
There is a whole universe of objects you could view at night, so where do you start?
We recommend starting with the most prominent objects first.
The moon
The moon is the easiest target to find at night. When the moon is in full position, it
bathes the night with a silvery light that washes the sky of all but the brightest objects.
The best time to view the moon is not when it is full, but rather when it is less than half
full. The dividing line between dark and light on the moon, called the terminator, shows
the best detail in the craters and mountains.
The planets
The planets, our solar system companions, range in size and substance from moon-size
rocky bodies to giant gas balls, which could hold Earth 1,000 times over. To find the
planets, you will need information about their times of visibility. An astronomy magazine
will give you the locations of the planets as they change position from month to month.
The Internet is also an excellent source of information, offering star charts, maps, and
more!
The popular and more familiar constellations often provide the easiest landmarks to
help find the planet’s locations and paths of orbit. Most people have looked up at the
sky at night and seen some of the planets without even realizing it. A planet looks like a
bright star but does not twinkle like a star does; it looks like a tiny ball. Venus, Mars,
Jupiter, and Saturn are the easiest planets to view. Mercury is dimmer, usually below
the horizon, and more challenging to find.
Each of the planets provides interesting views. Venus is covered with clouds so all that
is visible is an extremely bright light, the brightest next to the moon. However, Venus,
like the moon, goes through phases. As it travels around the sun, different areas of its
surface are illuminated, producing crescent shapes of varying sizes. Mars is the red
planet. When it is above the horizon, it is noticeably red and stands out like a beacon in
the night sky. The apparent brightness of Mars varies as the planet orbits around the
sun and throughout its period of visiblity, it will look brighter or dimmer depending on its
distance from Earth.
Jupiter is the largest planet in our solar system and the second brightest next to Venus.
Jupiter has many moons, four of which are often visible through your telescope when
viewing conditions permit. As you watch them throughout the evening, you will see that
they change position relative to each other and to Jupiter. It is possible with careful
planning to actually see one of the moons disappear either in front of or behind Jupiter
as it orbits around the planet.
Saturn, the second largest planet, is not as bright as Jupiter and so its moons are not as
visible through small telescopes. The large rings that encircle Saturn are spectacular to
observe, however.
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FREQUENTLY ASKED QUESTIONS
1) How far can I see?
If you stand outside and look up at the night sky on a clear evening, you can see
hundreds of stars without the aid of your telescope. The telescope is a light-gathering
instrument that magnifies the view—providing significantly more detail and unveiling
more stars, nebulae, and celestial objects. With the aid of a telescope, you will be able
to enjoy exciting views of Saturn’s rings, Jupiter’s major moons, the Orion Nebula, and
much more.
2) Why can’t I see anything through my telescope?
If you see only gray or black when looking through your telescope, even after searching
for an object to view, it is very likely that you are using a zoom power that is too
powerful. To solve this problem always start with the lowest power first, and only zoom
to the higher powers after you have located an object.
3) When I use my highest zoom power, everything looks much darker. Why?
As magnification in a telescope increases, brightness diminishes. Conversely,
brightness increases when magnification is reduced. If an image appears too dark or
unclear, use a lower power. Views of small, bright objects are superior to those of large,
dark, or blurry ones! Atmospheric conditions, air currents, as well as light and air
pollution also affect viewing quality.
4) As I look through my telescope, objects in the sky appear to move. Why is
that?
When you observe an astronomical subject through a telescope, the constant rotation of
the Earth makes things appear as though they are moving across the viewing area. If
you would like to reduce this effect of movement to a minimum and observe the widest
field of view, you should use lower zoom power.
!
WARNING! CHOKING HAZARD –
Small parts. Not suitable for children
under 3 years.
Made in China
Manual Part #: 264966
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