Orion StarBlast 4.5 User manual

1
The Claremont Galactic Space Viewer
Orion StarBlast 4.5” Reflector Telescope
INSTRUCTION MANUAL
Claremont Public Library
208 North Harvard Avenue
Claremont, CA 91711
[phone]
This telescope is made available by the Friends of the Claremont Library
(http://www.claremontlibrary.org/)
and fostered by the Pomona Valley Amateur Astronomers (http://pvaa.us/)
For telescope maintenance, please contact Mathew Wedel
m[email protected] (preferred) or [email protected]

2
"The best thing that we're put here for's to see;
The strongest thing that's given us to see with's
a telescope. Someone in every town
seems to me owes it to the town to keep one.
In Littleton it may as well be me."
Brad McLaughlin, quoted by Robert Frost
in “The Star Splitter”
And that works in Claremont, too!
WARNING: Never look directly at the Sun through your telescope or its finder scope —even
for an instant —as permanent eye damage could result. Do not point the telescope at the Sun, as
parts will melt! Children should use this telescope only with adult supervision.

3
Telescope Parts
1) Eyepiece
2) EZ Finder
3) Optical tube
4) Focuser
5) Tube Clamp
6) Altitude Clamp
7) Mirror Assembly (don‟t touch)
8) Support
9) Handle
10) Eyepiece rack
11) Eyepiece
12) Feet

4
Focuser Details
13) Focus wheels
14) Eyepiece securing thumb screws
EZ Finder Details

5
Getting Started
Please read the instructions and practice with the telescope inside before you take it out in the dark.
This is a “Push-to” telescope. Once you find what you are looking for, you can either watch the
object move through your “field of view” (what you see through the eye piece) and then reposition
the telescope, or keep pushing the scope to hold the object in the center of the eyepiece. Objects
appear to move across the field of view faster at higher magnifications. This is because the field of
view becomes narrower. You may find it helps to hold one hand near the carrying handle to steady
it while moving and aiming the telescope.
Like all Newtonian reflector telescopes, the image in the eyepiece is upside-down. Turning the
eyepiece won‟t help.
When looking at star charts or Moon maps, you will have to keep this in mind.
The Moon map on this telescope is “flipped” so it matches what you see in the eyepiece.
Do You Wear Eyeglasses? If you wear eyeglasses, you will probably be able to observe with your
glasses off by just refocusing the telescope to your unaided vision. If your eyes are astigmatic,
images will probably appear best with glasses on. This is because a telescope‟s focuser can
accommodate for nearsightedness or farsightedness, but not astigmatism.

6
Try out the telescope during the day:
The Zoom eye piece should be in the focuser and make sure it is secured with the two
thumbscrews. Remove the dust caps from the eyepiece and telescope tube.
Focusing the Telescope
Always start by using your lowest-power (turn the body of the Zoom so the pointer is at “24”) to
locate and center the object. Low magnification shows a larger area of sky in the eyepiece, making
finding and centering an object much easier.
With the eyepiece adjusted for low power (24 mm), aim the telescope in the general direction of an
object at least 1/4-mile away. Use a steeple, telephone pole, or a chimney. Slowly rotate the focus
wheels until the object comes into sharp focus. Go a little bit beyond sharp focus until the image
starts to blur again, then reverse the rotation of the knob, just to make sure you‟ve hit the exact
focus point.
Once you‟ve centered an object in the eyepiece, you can switch to a higher magnification by
twisting the Zoom„s barrel, if you wish. This is recommended for small and bright objects, like

7
planets and double stars. The Moon also takes higher magnifications well. You may have to
refocus a little after changing power.
If you find that it‟s awkward to put your eye up to the eyepiece, you can rotate the tube by
loosening the knob on the tube clamp and moving the optical tube until the focuser is in a
convenient position. Be sure to tighten it again!
You may find that the optical tube is either too hard to move or does not stay in place. Use the
altitude adjustment tension knob (it holds the telescope to the upright part of the base) to find the
right level of tension.
Operating the EZ Finder
A “finder scope” helps you find things. It‟s like a sight on a rifle. The EZ Finder works by
projecting a tiny red dot onto a lens mounted in the front of the unit, so that when you look through
the lens, the red dot will appear to float in space. Turn the power knob clockwise until you hear a
“click” indicating that power is on.
With your eye positioned at a comfortable distance, look through the back of the EZ Finder with
both eyes open to see the red dot. The intensity of the dot can be adjusted by turning the power
knob. Use the dimmest possible setting that allows you to see the dot without difficulty. At the end

8
of your observing session, be sure to turn the power knob counterclockwise until it clicks off. When
the two white dots on the EZ Finder‟s rail and power knob are lined up, the EZ Finder s turned off.
Aligning the EZ Finder
When the EZ Finder is properly aligned with the telescope, an object that is centered on the EZ
Finder‟s red dot should also appear in the center of the field of view of the telescope‟s eyepiece.
Alignment of the EZ Finder is easiest during daylight. Aim the telescope at a distant object at least
1/4 mile away, such as the top of a telephone pole or chimney and center it in the telescope‟s
eyepiece. Now, turn the EZ Finder on and look through it. The object will appear in the field of
view near the red dot. If the red dot is centered on the object in the eyepiece, you‟re done!
If not: Without moving the telescope, use the EZ Finder‟s left/right (azimuth) and up/down
(altitude) adjustment knobs to position the red dot on the object in the eyepiece.
When the red dot is centered on the distant object, make sure that the object is still centered in the
telescope‟s field of view. If not, re-center it and adjust the Finder‟s alignment again. When the
object is centered in the eyepiece and on the red dot, the Finder is properly aligned with the
telescope.
The finder scope has a battery pack attached to the telescope, instead of the stock “button” battery.
To change batteries, just slide the cover off the pack, and replace the two AAA batteries.

9
Fog on the mirrors and eyepieces: One of the odd things that happens when star gazing is that
dew forms on pretty much everything (and everyone). The big mirror is tucked safely down at the
bottom of the telescope, and so it does not get much dew on it. Eyepieces, however, often have
dew form on them, making them useless until they warm up and dry out. If the eyepiece fogs up,
remove it and put it in your pocket for a few moments. As it warms up, the fog should disappear.
If you have a hair dryer, or car window defroster handy, try heating it up there. Only use a plug-in
hair dryer that has a Ground Fault Interrupt attached. Please don‟t wipe the lens with a tissue or
cloth. The eyepiece has special coatings on it that could be damaged if you do. There is a Lens
Pen in the accessory pack. Use the brush to remove and dust, then use the „cup‟ (under the cap) to
clean the lens. This will not work for dew. Please ask people to not touch the lens… ever.
The image will be much better if let the telescope cool down to air temperature before you start
observing.
The Eyepiece chart on the telescope shows what magnification you will have for each setting of the
Zoom Eye piece. The “True Field” describes the width of the image in the eyepiece. A full Moon
is 30 minutes of a degree (or ½ of a degree) wide, so you could fit about 4 full Moons in the field of
view when using the 8mm setting. Change the Zoom setting until your target fits the eyepiece the
way you like. You will have to tweak the focus.

10
What to Expect
Planets will look small, but you should be able to see cloud bands on Jupiter and the rings of
Saturn. Craters on the Moon will be clear and numerous, the waxing and waning of Venus should
be visible, and many bright deep-sky objects will fill the eyepiece. Don‟t expect to see color as you
do in NASA photos as our eyes are not sensitive enough to see color in deep-sky objects, except in
a few of the brightest ones. Remember that you are seeing these objects using your own eyes! Each
session with your telescope will be a learning experience. Each time you work with the telescope, it
will get easier to use, and stellar objects will become easier to find.
Objects to Observe:
The Moon is one of the easiest and most interesting targets to view with your telescope. Lunar
craters, “seas”, and even mountain ranges can all be clearly seen from a distance of 238,000 miles
away! With its ever-changing phases, you‟ll get a new view of the Moon every night it‟s up. Make
sure to observe the Moon when it is well above the horizon to get the sharpest images. The best
time to observe is during a partial phase, that is, when the Moon is not full. During partial phases,
shadows are cast on the surface which reveals more detail, especially right along the border
between the dark and light portions of the disk (called the “terminator”). Use the Map on the
telescope tube to find the major craters and features.