Orion ASTROVIEW 9862 - Manual (Page 6)

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Focusing the telescope
You should now try to familiarize yourself with focusing the
telescope. With the 25mm eyepiece inserted in the diago-
nal, point the telescope in the general direction of an object
at least a 1/4 mile away. With your fingers, slowly rotate one
of the focus knobs until the object comes into sharp focus. If
the focuser motion is stiff, loosen the focus lock thumb screw
(Figure 3) until it moves more smoothly. Go a little bit beyond
sharp focus until the object starts to blur again, then reverse
the direction of the focus knob, just to make sure you’ve hit the
exact focus point.
NOTE: The image in the telescope will appear reversed
left-to-right. This is normal for astronomical refractor tele-
scopes that use a star diagonal. The finder scope view
will be rotated 180° (see Figure 5).
If you have trouble focusing, rotate the focus knob so the draw-
tube is in as far as it will go. Now look through the eyepiece
while slowly rotating the focusing knob in the opposite direc-
tion. You should soon see the point at which focus is reached.
You will have to re-adjust the focus when aiming at subjects of
varying distances, or after changing eyepieces.
Viewing with Eyeglasses
If you wear eyeglasses, you may able to keep them on while
you observe, if the eyepiece has enough “eye relief” to allow
you to see the whole field of view. You can try this by look-
ing through the eyepiece first with your glasses on, and then
with them off, and see if the glasses restrict the view to only a
portion of the full field. If they do, you can easily observe with
your glasses off by just re-focusing the telescope the needed
amount. If you suffer from severe astigmatism, however, you
may find images noticeably sharper with your glasses on.
aligning the Finder scope
The AstroView 100 EQ comes with a 6x30 achromatic finder
scope (Figure 2a). The number 6 means six-times magnifi-
cation and the 30 indicates a 30mm diameter front lens. The
finder scope makes it easier to locate the subject you want
to observe in the telescope, because the finder scope has a
much wider field of view.
The AstroView 100 EQ’s finder scope uses a spring-loaded
bracket that makes alignment of the finderscope very easy. As
you turn either of the thumbscrews, the spring in the bracket’s
tensioner moves in and out to keep the finder scope secure in
the bracket.
The finder scope must be aligned accurately with the tele-
scope for proper use. To align it, first aim the main telescope in
the general direction of an object at least a 1/4 mile away-the
top of a telephone pole, a chimney, etc. To aim the telescope,
loosen the R.A. and Dec. lock levers and move it until it is
pointing at the desired object. Sight along the tube for easi-
est aiming. Turn the focus knob until the object is properly
focused. Center the object in the telescope’s eyepiece by turn-
ing the R.A. and Dec. slow-motion controls.
Now look in the finder scope. Is the object visible? Ideally it will
be somewhere in the field of view. If not, some coarse adjust-
ment to the finder scope bracket’s alignment thumbscrews will
be needed until the object comes into the finder scope’s field
of view.
With the image in the finder scope’s field of view, you can now
fine-adjust the alignment thumbscrews to center the object on
the intersection of the crosshairs. Adjust the aim of the finder
scope by turning the thumbscrews, one at a time, until the
object is centered.
The finder scope alignment needs to be checked before every
observing session. This can easily be done at night, before
viewing through the telescope. Choose any bright star or plan-
et, center the object in telescope eyepiece, and then adjust
the finder scope bracket’s alignment thumbscrews until the
star or planet is centered on the finder’s crosshairs.
Focusing the finder scope
If, when you look through the finder scope, the images appear
somewhat out of focus, you will need to refocus the finder
scope for your eyes. Loosen the lock ring located behind the
objective lens cell on the body of the finder scope (see Figure
2a). Back the lock ring off by a few turns, for now. Refocus the
finder scope on a distant object by threading the objective lens
cell in or out of the finderscope body. Precise focusing will be
achieved by focusing the finder scope on a bright star. Once
the image appears sharp, retighten the lock ring behind the
objective lens cell. The finder scope’s focus should not need
to be adjusted again.
4. setting up and using the
Equatorial Mount
When you look at the night sky, you no doubt have noticed that
the stars appear to move slowly from east to west over time.
That apparent motion is caused by the Earth’s rotation (from
west to east). An equatorial mount (Figure 6) is designed to
compensate for that motion, allowing you to easily “track” the
Figure 5. Images through the finder scope will appear upside-
down and backwards (rotated 180°). Images through the AstroView
100 EQ with its diagonal in place will be reversed from left-to right.
View through the AstroView 100 EQ
View through finder scope