Orion STARBLAST 6 9964 - Manual (Page 6)

6
skies and a bright setting is used under light-polluted skies
or in daylight.
At the end 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 II’s rail and power knob are
lined up, the EZ Finder II is turned off.
aligning the EZ Finder ii
When the EZ Finder II is properly aligned with the tele-
scope, an object that is centered on the EZ Finder II’s red
dot should also appear in the center of the field of view of
the telescope’s eyepiece. Alignment of the EZ Finder II is
easiest during daylight, before observing at night. Aim the
telescope at a distant object at least 1/4 mile away, such as
a telephone pole or chimney and center it in the telescope’s
eyepiece. Now, turn the EZ Finder II on and look through it.
The object will appear in the field of view near the red dot.
Note: The image in the eyepiece of the StarBlast 6 will be
upside-down (rotated 180°). This is normal for Newtonian
reflector telescopes.
Without moving the telescope, use the EZ Finder II’s azi-
muth (left/right) and altitude (up/down) adjustment knobs
(Figure 6) to position the red dot on the object in the eye-
piece.
When the red dot is centered on the distant object, check to
make sure the object is still centered in the telescope’s field
of view. If not, recenter it and adjust the EZ Finder II’s align-
ment again. When the object is centered in the eyepiece
and on the red dot, the EZ Finder II is properly aligned with
the telescope. Figure 7 shows how the view through the EZ
Finder may look while you are aligning it.
Once aligned, EZ Finder II will usually hold its alignment
even after being removed and remounted. Otherwise, only
minimal realignment will be needed.
replacing the EZ Finder ii Battery
Replacement 3-volt lithium batteries for the EZ Finder II are
available from many retail outlets. Remove the old battery
by inserting a small flat-head screwdriver into the slot on the
battery casing (Figure 6) and gently prying open the case.
Then carefully pull back on the retaining clip and remove
the old battery. Do not overbend the retaining clip. Slide the
new battery under the battery lead with the positive (+) side
facing down and replace the battery casing.
using your telescope
Choosing an observing Site
When selecting a location for observing, get as far away as
possible from direct artificial light such as street lights, porch
lights, and automobile headlights. The glare from these
lights will greatly impair your dark-adapted night vision.
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 temperature 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 significantly from night to night.
“Seeing” refers to the steadiness of the Earth’s atmosphere
at a given time. In conditions of poor seeing, atmospheric
turbulence causes objects viewed through the telescope to
“boil”. If, when you look up at the sky with your naked eyes,
the stars are twinkling noticeably, the seeing is bad and you
will be limited to viewing with low powers. This is because
bad seeing affects images at high powers more severely.
Planetary observing may also be poor.
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 bet-
ter 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 (6th magnitude or
fainter is desirable).
If you cannot see stars of magnitude 3.5 or dimmer then
conditions are poor. Magnitude is a measure of how bright
Figure 7.
The EZ Finder
II superimposes
a tiny red dot on
the sky, showing
right where the
telescope
is
pointed.
Figure 6. The EZ Finder II reflex sight.
Power knob
Azimuth
adjustment
knob
Battery
casing
Mounting bracket Altitude
adjustment
knob