DEEP SPACE SERIES
675 x 4.5” Reflector Telescope
Model 78-9518
1
2
17
16
fig. 1
3
15
14
13
4
5
6
7
12
11
9
10
8
13. Horizontal Axis Lock
1. Finderscope
14. Primary Mirror (Internal)
15. Telescope Main Tube
2. Finderscope Mount
3. Rack & Pinion Focusing
Mechanism
e
16. Finderscope Focus Adjustm
17. Finderscope Adjustment
4. Eyepiece
Screws (3)
5. Fine Adjustment Cables (2)
18. Declination Lock Knob
19. Declination Scale
20. Equatorial Mount
21. Right Ascension Lock Knob
22. Latitude Lock Knob
23. Latitude Scale
6. Counterweight
7. Counterweight Shaft
See pg. 2 (fig. 1)
8. Tripod Leg Middle Section
9. Accessory Tray Brace
10. Accessory Tray
11. Tripod Leg Lock Screws
12. Tripod Leg
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 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
will be 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 (20) 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
ANSWERS TO COMMONLY ASKED QUESTIONS
1. The image I see in the telescope is upside down and
·
An upside-down and reversed image is a common
reversed from right to left ?
characteristic of all refractor telescopes. Since
telescopes are used for astronomical viewing
orientation is not important. An erecting lens can be
purchased separately that will allow you to see a
“natural” image. 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
·
·
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 450mm
to 1000mm on Bausch & Lomb, Bushnell and Jason
telescopes. Typical focal lengths are 600mm,
700mm, and 900 (Jason); 450, 750 and 910
(Bushnell); 900, 910 and 1000 for Bausch & Lomb.
4. What can I see with my telescope ?
·
·
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
1. I’ve completed the set-up yet I cannot see anything
·
Check to see if objective lens cover has been
removed.
·
·
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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