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Orion 9820 Instruction Manual page 6

Maksutov-cassegrain optical tube assemblies

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No surface markings can be seen on Venus, which is always
shrouded in dense clouds.
MARS If atmospheric conditions are good, you may be able
to see some subtle surface detail on the Red Planet, possibly
even the polar ice cap. Mars makes a close approach to Earth
every two years; during those approaches its disk is larger
and thus more favorable for viewing.
C. Stars
Stars will appear like twinkling points of light in the telescope.
Even the largest telescopes cannot magnify stars to appear
as anything more than points of light. You can, however, enjoy
the different colors of the stars and locate many pretty double
and multiple stars. The famous "Double-Double" in the con-
stellation Lyra and the gorgeous two-color double star Albireo
in Cygnus are favorites. Defocusing the image of a star slight-
ly can help bring out its color.
D. Deep-Sky Objects
Under dark skies, you can observe a number of brighter
deep-sky objects with the Apex telescopes, including
gaseous nebulas, open and globular star clusters, and the
brighter galaxies. Most deep-sky objects are very faint, so it is
important that you find an observing site well away from light
pollution. Take plenty of time to let your eyes adjust to the
darkness. Don't expect these objects to appear like the pho-
tographs you see in books and magazines; most will look like
dim gray "ghosts." (Our eyes are not sensitive enough to see
color in deep-sky objects except in few of the brightest ones.)
But as you become more experienced and your observing
skills improve, you will be able to coax out more and more
intricate details.
Photography
When coupled to a 35mm single-lens reflex camera, the Apex
becomes a telephoto lens. For terrestrial or astronomical pho-
tography, you need only a T-ring for your specific camera
model. The T-ring attaches to your camera and threads onto
the Apex's eyepiece adapter (see Figure 6).
Use the camera's viewfinder to frame the picture. Use the
telescope's focuser to focus the image. You may want to con-
sider using a remote shutter release instead of the shutter
release on the camera; touching the camera can vibrate the
system and blur the resulting photographic image on the film.
Also, be sure to use a solid tripod.
Knurled ring
Eyepiece adapter
T-ring
6
If you would like to change the orientation of the camera rela-
tive to the telescope, do so by first loosening the knurled ring
located in front of the eyepiece adapter (see Figure 6). You
can then rotate the camera (and eyepiece adapter) to the
desired orientation. Retighten the knurled ring when done.
Care & Maintenance
Transporting and Storing
The included soft carry case provides an excellent way to
transport and store the optical tube and its accessories. To
place the optical tube in the case, the eyepiece, diagonal,
finder scope and bracket must be removed from the tube.
When removing the eyepiece and diagonal, remember to first
loosen the securing thumb screws. The finder scope and
bracket can be removed together by loosening the thumb
screw on the tube's dovetail holder. Cover the front of the opti-
cal tube with the dust cover and the rear opening of the
eyepiece adapter with its cap. Now place the tube in the
case's main compartment. The finder scope and bracket can
also be placed in the main compartment. Use the included
removable padded divider or padded tray to separate the find-
er scope and bracket from the optical tube. The Apex 90mm
and Apex 102mm come with one small padded divider and
one padded tray. The Apex 127mm comes with one padded
tray only. The padded tray will be on the bottom of the main
compartment of the case when it is shipped to you. For the
Apex 90mm, use the small divider to separate the finder
scope and bracket from the optical tube. For the Apex 102mm
and Apex 127mm, position the padded tray on top of the opti-
cal tube; the finder scope and bracket can be stored on top of
the tray so they will not damage the tube. The eyepiece and
diagonal should be covered with their caps and placed in the
external compartments of the case.
If you give your telescope reasonable care, it will last a life-
time. Store it in a clean, dry, dust-free place, safe from rapid
changes in temperature and humidity. Do not store the tele-
scope outdoors, although storage in a garage or shed is OK.
Cleaning the tube
Your Apex Maksutov-Cassegrain telescope requires very little
mechanical maintenance. The optical tube is aluminum and
has a smooth painted finish that is fairly scratch-resistant. If a
scratch does appear on the tube, it will not harm the tele-
scope. If you wish, you may apply some auto touch-up paint
to the scratch. Smudges on the tube can be wiped off with a
soft cloth and a household cleaner such as Windex or
Figure 6: A T-ring
Formula 409.
is all that is
needed to
Cleaning Lenses
connect a 35mm
Any quality optical lens cleaning tissue and optical lens clean-
SLR camera to
ing fluid specifically designed for multi-coated optics can be
the Apex
used to clean the Apex's front meniscus lens or exposed lens-
telescopes; it
es of your eyepieces or finder scope. Never use regular glass
cleaner or cleaning fluid designed for eyeglasses. Before
threads onto the
cleaning with fluid and tissue, however, blow any loose parti-
eyepiece adapter
cles off the lens with a blower bulb or compressed air. Then
with eyepiece
apply some cleaning fluid to a tissue, never directly on the
and diagonal
optics. Wipe the lens gently in a circular motion, then remove
removed.
any excess fluid with a fresh lens tissue. Oily fingerprints and

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