Bushnell DEEP SPACE 78-9518 User Manual
Page 3
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