675 x 4.5” Reflector Telescope
Model 78-9675
1
2
17
16
3
4
fig. 1
15
14
13
5
6
7
12
11
9
10
8
13. Horizontal Axis Lock
1. Finderscope
2. Finderscope Mount
14. Primary Mirror (Internal)
15. Telescope Main Tube
3.
Rack & Pinion Focusing
Mechanism
16. Finderscope Focus Adjustmen
17. Finderscope Adjustment
4.
Eyepiece
Screws (3)
5. Fine Adjustment Cables (2)
18. Declination Lock Knob
6. Counterweight
19. Declination Scale
7. Counterweight Shaft
20. Equatorial Mount
8. Tripod Leg Middle Section
See pg. 2 (fig. 1)
21. Right Ascension Lock Knob
22. Latitude Lock Knob
9.
Accessory Tray Brace
10. Accessory Tray
11. Tripod Leg Lock Screws
12. Tripod Leg
23. Latitude Scale
24. Right Ascension Scale
25. Cradles
3. Locate the Counterweight (6) and Counterweight Shaft (7). Loosen the thumb screw located on the
Counterweight and slide the Counterweight onto the Counterweight Shaft, then and tighten thumb screw to
secure the Counterweight. Thread the Counterweight Shaft into the hole located directly below the
Declination Lock Knob (18). Make sure that the shaft is securely locked into mount.
4. Insert Eyepiece (4) into focusing tube to begin viewing.
Your Bushnell Voyager Telescope is now ready to be used. To obtain the fullest enjoyment
from your telescope, please refer to the additional information below.
HOW TO USE YOUR NEW TELESCOPE
Astronomical telescopes are designed in such a way that the image you will see appear
UPSIDE DOWN and REVERSED, this is acceptable for viewing celestial bodies.
Selecting an Eyepiece:
1. You should always start viewing with the lowest power eyepiece, which in this case is the 20 mm lens.
Note: the base power of each eyepiece is determined by the focal length of the telescope objective lens,
which for this model is 900 mm. A formula can be used to determine the power of each eyepiece:
telescope OBJECTIVE lens focal length EYEPIECE focal length = MAGNIFICATION (e.g. Using the
20 mm lens, the calculation would look like this: 900 mm ¸ 20mm = 45x or 45 power.)
2. Included with this telescope is a Barlow lens. Barlow lenses are used to double or triple the power of your
telescope. Place your Barlow between the focusing tube and the eyepiece. Using the example above,
your 3x Barlow lens would give you a total power of 135x or 135 power. (45 x 3 = 135x or 135 power)
Focusing Telescope:
1. After selecting the desired eyepiece, aim main telescope tube at a land-based target at least 200 yards
away (e.g. A telephone pole or building). Fully extend focusing tube by turning Rack and Pinion Focusing
Mechanism (3).
2. While looking through selected eyepiece (in this case the 20 mm), slowly retract focusing tube by turning
Rack and Pinion Focusing Mechanism until object comes into focus.
Aligning Finderscope:
1. Look through Main Telescope Tube (15) and establish a well-defined target. (see focusing telescope
section) Tighten all lock knobs (Declination, Latitude, Right Ascension, Horizontal Axis and Cradle) so
that telescope’s aim is not disturbed.
2. Looking through Finderscope (1), alternate tightening each Finderscope Adjustment Screw (17) until
crosshairs of Finderscope are precisely centered on the same object already centered in Main Telescope
Tube's(15) field of view.
3. Now, objects located first with the Finderscope (1) will be centered in the field of view of the main
telescope.
Balancing the Telescope
1. Arrange the telescope so that the telescope body is horizontal to the floor (latitude of 0°). Loosen the
Right Ascension Lock (21). The telescope should now turn freely about the polar axis. Rotate the telescope
about the polar axis so that the Counterweight Shaft (7) is parallel to the ground (horizontal).
2. Loosen the Counterweight Lock Screw (located on the counterweight), and slide the Counterweight (6) along
the shaft until the telescope remains stationary without drifting rotationally about the polar axis. Tighten
the Counterweight Lock Screw, locking the Counterweight into position.
3. Now balance the telescope about the Declination Axis. Loosen the Declination Lock Screw (18) and the
Cradle Lock Knobs (fig. 3)so that the telescope can slide freely inside the Cradles (25). Slide the telescope
up or down inside the rings until the telescope remains stationary without drifting rotationally about the
Declination Axis. Tighten Cradle Lock Knobs. The telescope is now balanced.
Cradle (25)
Cradle Lock Knob
Fig. 3
UNDERSTANDING THE
EQUATORIAL MOUNT
The Equatorial Mount (20) is designed to move in any direction. It can be set to allow
manual controls to track the movements of celestial bodies across the sky. This is
referred to as diurnal movement; movement of celestial bodies in the direction
opposite to that of the earth’s rotation and is around the earth’s axis.
By aligning the telescope’s polar axis at celestial North, you will place the
telescope in parallel with the earth’s axis and thus be able to locate stars in the sky
based on star atlas information. To compensate for your position on earth, the
polar axis is set in one of three ways:
·
·
·
Set up the telescope at night. Loosen the Declination Lock Knob (18) and rotate
the telescope around the declination axis until the arrow on the declination
scale points to 90 degrees. Tighten the Declination Lock Knob. The telescope is
now roughly in parallel with the polar axis.
Loosen the Horizontal Axis Lock Knob (13) and turn the telescope until the
objective end faces due north. This can be done by approximating the location of the pole star (Polaris or
North Star) or by the use of a compass. True North is then found by directing the telescope at Polaris, as
magnetic North is slightly away from true North.
Look up the latitude of your area in any geographical atlas. Loosen the Latitude Lock Knob (22) and set
the latitude scale to the correct latitude for your area. Aim the Finderscope (1) at Polaris. You will probably
notice that Polaris is not dead center in the Finderscope’s field of view. This is probably because your
telescope is not absolutely level with the ground. Loosen the Horizontal Axis Lock Knob (13) again and
turn the telescope so that it is directly aimed at Polaris. Tighten both the Horizontal Axis Lock Knob and
Latitude Lock Knob. Polaris is 1 degree from the North celestial pole. Therefore, the sighting of stars will
have to be slightly adjusted as you locate them in the heavens.
Never Look Directly At The Sun With Your Telescope
Permanent Damage To Your Eyes May Occur
Enjoying Your New Telescope
1. First determine your targeted object. Any bright object in the night sky is a good starting point. One of the
favorite starting points in astronomy is the moon. This is an object sure to please any budding astronomer or
experienced veteran. When you have developed proficiency at this level, other objects become good
targets. Saturn, Mars, Jupiter, and Venus are good second steps to take.
2. Avoid the temptation to move directly to the highest power. The low power eyepiece will give you a
wider field of view, and brighter image--thus making it very easy to find your target object. At this point
with a focused image, you've passed the first obstacle. Once you pass this step, you'll will enjoy the time
spent with your telescope. Every celestial object you center in the telescope will be easily focused, which is
important for continuing your exploration of the night sky.
3. The low power eyepieces are perfect for viewing the full moon, planets, star clusters, nebulae, and even
constellations. These should build your foundation. However, for more detail, try bumping up in
magnification to higher power eyepieces on some of these objects. During calm and crisp nights, the
light/dark separation line on the moon (called the "Terminator") is marvelous at high power. You can see
mountains, ridges and craters jump out at you due to the highlights. Similarly, you can move up to higher
magnifications on the planets and nebulae. Star clusters and stars are best viewed through the low power
no matter what.
4. The recurring astronomical theater we call the night sky is an ever-changing billboard. In other words, not
the same movie plays all the time. Rather, the positions of the stars change not only hourly as they seem
to rise and set, but also throughout the year. As the earth orbits the sun our perspective on the stars changes
on a yearly cycle about that orbit. The reason the sky seems to move daily just as the sun and the moon
"move" across our sky, is that the earth is rotating about its axis. As a result you may notice that after a
few minutes or a few seconds depending on what power you are viewing at, the objects in your telescope will
move. At higher magnifications especially, you will notice that the moon or Jupiter will "race" right out of
the field of view. To compensate, just move your telescope to "track" it in the necessary path.
Helpful Hints
Your telescope is a very sensitive instrument. For best results and fewer vibrations set your telescope up on a
level location on the ground rather than your concrete driveway or your wooden deck. This will provide a more
stable foundation for viewing, especially if you've drawn a crowd with your new telescope.
If possible view from a location that has relatively few lights. This will allow you to see much fainter objects.
You'd be surprised how much more you'll see from your local lake or park when compared to a backyard in the
city.
Using your telescope out a window is NEVER recommended.
View objects that are high in the sky if possible. Waiting until the object rises well above the horizon will
provide a brighter and crisper image. Objects on the horizon are viewed through several layers of earth's
atmosphere. Ever wonder why the moon appears orange as it sets on the horizon. It's because you are looking
through a considerable more amount of atmosphere than you would directly overhead. (Note: If objects high in
the sky are distorted or wavy, you are probably viewing on a very humid night.) During nights of unstable
atmosphere, viewing through a telescope can be frustrating if not impossible. Astronomers refer to crisp, clear
nights as nights of "good seeing."
Where do I start?
Your Bushnell telescope can bring the wonders of the universe to your eye. While this manual is intended to
assist you in the set-up and basic use of this instrument, it does not cover everything you might like to know
about astronomy. The first thing you need to do is get a very simple star chart and a flashlight with a red bulb
or red cellophane over the end. For objects other than stars and constellations, a basic guide to astronomy is a
must. Some recommended sources appear on our website at www.bushnell.com. Also on our website will be
current events in the sky for suggested viewing. But, some of the standbys that you can see are:
The Moon--a wonderful view of our lunar neighbor can be enjoyed with any magnification. Try viewing at
different phases of the moon. Lunar highlands, lunar maria (lowlands called "seas" for their dark coloration),
craters, ridges and mountains will astound you.
Saturn--even at the lowest power you should be able to see Saturn's rings and moons. This is one of the most
satisfying objects in the sky to see simply because it looks like it does in pictures. Imagine seeing what you've
seen in textbooks or NASA images from your backyard!
Jupiter--the largest planet in our solar system is spectacular. Most noted features are its dark stripes or bands
both above and below its equator. These are the north and south equatorial belts. Also interesting are Jupiter's
four major moons. Pay close attention to their positions from night to night. They appear to be lined up on
either side of Jupiter.
Mars--The Great Red Planet appears as a reddish-orange disk. Look at different times of the year and try to
catch a glimpse of the white polar ice caps.
Venus--just like the moon, Venus changes phases from month to month. Some views of brilliant Venus appear as
if you were looking at a distant crescent moon.
Nebulae--The Great Orion Nebula is a very well known night sky object. This and many others are brought to
you by this telescope.
Star Clusters--View millions of stars densely packed in a cluster that resembles a ball.
Galaxies--One of the greatest and most interesting galaxies is our neighbor the Andromeda Galaxy. Enjoy this
and many others.
ANSWERS TO COMMONLY ASKED QUESTIONS
1. The image I see in the telescope is upside down and
reversed from right to left ?
·
·
·
·
An upside-down and reversed image is a common
characteristic of most astronomical telescopes. Since
telescopes are used for astronomical viewing
orientation is not important. The image in the
finderscope will also be upside down and reversed.
2. How do I determine the power my telescope ?
3. Where do I find the Telescope Focal Length
4. What can I see with my telescope ?
The power of your telescope can be determine by
dividing the focal length of the objective lens by the
focal length of the eyepiece. The eyepiece focal length
is the number printed on the eyepiece. (For example:
1000 ¸ 25 = 40X)
The telescope focal length is the same focal length as
the objective focal length. For this telescope it is
900mm. Telescope focal lengths range from 600mm
to 900mm on Bausch & Lomb, Bushnell and Jason
telescopes.
Telescopes with power ranging from 25X to 50X can
be used to view Star Clusters and Nebulae. 90X to
120X telescope can view galaxies. Most planets can
be seen at 150X and higher.
5. What do the numbers on the eyepiece mean ?
·
The numbers on the eyepiece represents the “focal
Length” of the eyepiece.
TROUBLESHOOTING GUIDE
If after you have set-up your new telescope you are unable to see any objects, use this Quick
Reference guide to help you to understand the cause of the problem and quickly determine a remedy
I’ve completed the set-up yet I cannot see anything
·
·
Try to view an object that is 200 or more yards away.
If there is more than one eyepiece included with the
telescope, use the lowest power (highest number)
eyepiece to begin viewing.
·
Use the Rack & Pinion Focusing Mechanism (3) to
bring the object you are trying to view into focus
Telescope LIFETIME LIMITED WARRANTY
Your telescope is warranted to be free of defects in materials and workmanship for the lifetime
of the original owner. The Lifetime Limited Warranty is an expression of our confidence in the
materials and mechanical workmanship of our products and is your assurance of a lifetime of
dependable service.
If your telescope contains electrical components the electronic components are warranted to be
free of defects in materials and workmanship for one year after the date of purchase.
In the event of a defect under this warranty, we will, at our option, repair or replace the
product, provided that you return the product postage prepaid. This warranty does not cover
damages caused by misuse or improper handling, installation or maintenance of the product.
Any return made under this warranty must be accompanied by the items listed below:
1) A check in the amount of $15.00 to cover the cost of handling
2) Name and address for product return
3) An explanation of the defect
4) Product should be well packed in a sturdy outside shipping carton to prevent
damage in transit and return postage prepaid to the address listed below:
IN U.S.A. Send To:
Bushnell * 8500 Marshall Drive * Lenexa, Kansas 66214
IN CANADA Send To:
Bushnell * 25A East Pearce Street, Unit 1 * Richmond Hill, Ontario L4B 2M9
For products purchased outside the United States and Canada please contact your local dealer
for applicable warranty information. This warranty gives you specific legal rights. You may
have other rights which vary from country to country.
©2001 Bushnell Performance Optics
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