Bushnell 78-4500 User Manual

VOYAGER® 4.5 INCH DOBSONIAN TELESCOPE

MODEL 78-4500

1. Rack & Pinion Focusing System 5. Dobsonian Base (Azimuth Bearing)

2. Reflector Body 6. Primary Mirror

3. Altitude Bearing 7. Finderscope

4. Dobsonian Side Panel 8. 1.25” Format Eyepiece

Never Look Directly At The Sun With Your Telescope

Permanent Damage To Your Eyes May Occur

Thank you for purchasing the Bushnell Voyager Dobsonian Telescope! Your new telescope has
been designed and crafted with the highest standards so that you may have years of enjoyment
and use out of this wonderful window to the heavens. This product comes complete with
everything you'll need to explore your universe including a professional primary mirror,
precision rack and pinion focusing mechanism, superior all-metal main telescope tube, and
professional quality wide-field 5x24mm finderscope. Whether you are just starting out in
astronomy or you are an avid astronomer we wish you all the best with your telescope.

Please utilize this manual to its fullest potential by reading it completely before you attempt to
assemble and use your new telescope. Once assembled, we've included a basic guide on how to
get started in astronomy at the end of this manual. While this is not a complete guide, it will give
you some initial pointers. As you advance in ability, we would highly recommend a
supplemental star atlas, beginning astronomy guide, moon map, or any other guide as you travel
on your journey through the universe.

READ THROUGH ASSEMBLY INSTRUCTION

BEFORE YOU ASSEMBLE YOUR TELESCOPE

TELESCOPE ASSEMBLY INSTRUCTIONS

Your Bushnell Voyager Dobsonian Telescope comes preassembled from the factory. By simply
attaching the accessory finderscope and eyepiece, you will be ready to explore.

ATTACH FINDERSCOPE

1. Remove Reflector Telescope Assembly (2) and Finderscope (7) from carton.

2. Remove nuts located near the Rack & Pinion Focusing Mechanism (1) on Reflector Telescope
Body (2).

3. Attach Finderscope (7) to Reflector Telescope Body (2) by inserting the bolts extending from
the Reflector Telescope Body (2) into the holes in the base of the Finderscope (7).

4. Refasten nuts so that Finderscope (7) is secure.

THE FINAL STEPS

1. Remove 1.25" Format Eyepiece (8) from carton.

2. Insert into Rack & Pinion Focusing Mechanism (1).

3. Remove Protective Dust Cover from end of telescope nearest the Rack & Pinion Focusing
Mechanism (1).

4. Let the adventure begin.

Your Bushnell Telescope is now ready to be used. To obtain the fullest enjoyment from your
telescope, please refer to the following additional information.

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.

TELESCOPE USE

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 element, which for this model is 900 mm. A formula can be used to
determine the power of each eyepiece: telescope OBJECTIVE mirror 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 81x or 81
power. (27 x 3 = 81x or 81 power)

3. Other accessories available include a 9mm eyepiece (model #78-0101) and a standard camera
adapter (model #78-0104) for photographing the night sky.

FOCUSING TELESCOPE:

1. After inserting the eyepiece, aim the 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 &
Pinion Focusing Mechanism (1)

2. While looking through selected eyepiece (in this case the 20 mm), slowly retract focusing
tube by turning Rack & Pinion Focusing Mechanism (1) until object comes into focus.

ALIGNING FINDERSCOPE:

1. Look through low-power 1.25" format eyepiece (8) and establish a well-defined target (see
focusing telescope section).

2. Looking through Finderscope (7), alternate tightening each Finderscope Adjustment Screw
surrounding the Finderscope (7) in the Finderscope Mount until crosshairs of Finderscope (7)
are precisely centered on the same object already centered in Main Telescope Tube's field of
view as seen through the 1.25" Format Eyepiece (8).

3. Now, objects located first with the Finderscope (7) will be centered in the field of view of the
main telescope as seen through the 1.25" Format Eyepiece (8).

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. The first thing you need to do after assembling the telescope as planned is center the desired
object in the finderscope's cross hairs. Provided you did a reasonable job aligning the
finderscope, a quick look through the main telescope tube at low power should reveal the
same image. With the lowest power eyepiece (the one with the largest number printed on it)
you should be able to focus the same image that you saw through the finderscope. 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.