ORION TELESCOPES & BINOCULARS Observer II User Manual

5
mination. Typically the dimmer setting is used under dark
skies and the brighter setting is used under light-polluted
skies or in daylight. Position your eye at a comfortable dis-
tance from the rear of the unit. Look through the rear of the
nder scope with both eyes open to see the illuminated
red dot. The target object should appear in the eld of view
somewhere near the red dot.
5. You’ll want to center the target object on the red dot. To do
so, without moving the telescope, use the nder scope’s
vertical and horizontal adjustment knobs (shown in Figure
12) to position the red dot on the object.
6. When the red dot is centered on the distant object, check
to make sure the object is still centered in the telescope’s
eyepiece. If it isn’t, re-center it then adjust the finder
scope’s alignment again. When the object is centered in
the telescope eyepiece and on the nder scope’s red dot,
the nder scope is properly aligned with the telescope.
The red dot nder scope’s alignment should be checked
before every observing session.
At the end of your observing session, be sure to slide the
power switch on the red dot nder scope to OFF to preserve
battery life.
Understanding the “Altazimuth” Mount
Observer II 60mm Altazimuth Refractor features an “altaz-
imuth” mount, which permits motion along two perpendicular
axes: altitude (up/down) and azimuth (left/right) (see Figure
2). This makes pointing the telescope easy and intuitive. To
move the telescope in the azimuth direction, loosen the azi-
muth lock knob, take hold of the telescope and gently rotate it
to the desired position. Then re-tighten the azimuth lock knob.
To move the telescope in the altitude direction, loosen the alti-
tude lock knob then move the tube up or down to the desired
position. Then retighten the altitude lock knob. If the telescope
moves too freely in the in the altitude direction, then tighten up
the yoke knobs a bit. Of course, you can move the telescope
in altitude and azimuth simultaneously by loosening both of
the lock knobs.
Because making ne-adjustments in the altitude of the tele-
scope can be difficult, the Observer II 60mm comes equipped
with an altitude micro-motion rod and thumbwheel (Figure 13).
After making coarse altitude adjustments by moving the tube
by hand, you can then move the telescope incrementally by
turning the micro-motion rod’s thumbwheel (the altitude lock
knob must be tightened for this). The telescope will move a
very small amount either up or down, depending on which
direction you turn the thumbwheel. Fine motion can be helpful
when centering an object in the eyepiece
4. Astronomical Observing
For many, this will be your rst foray into the exciting world of
amateur astronomy. The following information and observing
tips will help get you started.
Choosing an Observing Site
When selecting a location for observing, get as far away as
possible from direct articial light such as street lights, porch
lights, and automobile headlights. The glare from these lights
will greatly impair your dark-adapted night vision. Set up on
a grass or dirt surface, not asphalt, because asphalt radiates
more heat. Heat disturbs the surrounding air and degrades
the images seen through the telescope. Avoid viewing over
rooftops and chimneys, as they often have warm air currents
rising from them. Similarly, avoid observing from indoors
through an open (or closed) window, because the tempera-
ture difference between the indoor and outdoor air will cause
image blurring and distortion.
If at all possible, escape the light-polluted city sky and head
for darker country skies. You’ll be amazed at how many more
stars and deep-sky objects are visible in a dark sky!
“Seeing” and Transparency
Atmospheric conditions vary signicantly from night to night.
“Seeing” refers to the steadiness of the Earth’s atmosphere at
a given time. In conditions of poor seeing, atmospheric turbu-
lence causes objects viewed through the telescope to “boil.”
If you look up at the sky and stars are twinkling noticeably,
the seeing is poor and you will be limited to viewing at lower
magnications. At higher magnications, images will not focus
clearly. Fine details on the planets and Moon will likely not be
visible.
In conditions of good seeing, star twinkling is minimal and
images appear steady in the eyepiece. Seeing is best over-
head, worst at the horizon. Also, seeing generally gets better
after midnight, when much of the heat absorbed by the Earth
during the day has radiated off into space.
Especially important for observing faint objects is good
“transparency”—air free of moisture, smoke, and dust. All
tend to scatter light, which reduces an object’s brightness.
Transparency is judged by the magnitude of the faintest stars
you can see with the unaided eye (5th or 6th magnitude is
desirable).
Cooling the Telescope
All optical instruments need time to reach “thermal equilibri-
um.” The bigger the instrument and the larger the temperature
Figure 5.
a) Attach the three tripod legs to the yoke mount,
making sure the bolt’s hex-shaped head seats in the hex-shaped
recess of the tripod leg. b) Place a washer and wing nut on the
exposed end of the bolt.
b.a.
Yoke Mount
Washer
Wing nut
Hex-shaped hole
Tripod
leg

ORION TELESCOPES & BINOCULARS Observer II Specifications

General

Brand	ORION TELESCOPES & BINOCULARS
Model	Observer II
Category	Telescope
Language	English