Orion 9966 - Manual (Page 17)

17
possible to take pictures of bright objects. Certain photo-
graphic aids, such as the Orion SteadyPix, can help in taking
photos by the afocal method.
6. Care and Maintenance
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.
Small components like eyepieces and other accessories
should be kept in a protective box or storage case. Keep the
cap on the front of the telescope when it is not in use.
The telescope requires very little mechanical maintenance.
The optical tube is steel and has a smooth painted finish that
is fairly scratch-resistant. If a scratch does appear on the
tube, it will not harm the telescope. Smudges on the tube can
be wiped off with a soft cloth and a household cleaning fluid.
Cleaning Lenses
Any quality optical lens cleaning tissue and optical lens clean-
ing fluid specifically designed for multi-coated optics can be
used to clean the exposed lenses of your eyepieces or find-
er scope. Never use regular glass cleaner or cleaning fluid
designed for eyeglasses. Before cleaning with fluid and tissue,
however, blow any loose particles off the lens with a blower
bulb or compressed air. Then apply some cleaning fluid to a
tissue, never directly on the optics. Wipe the lens gently in
a circular motion, then remove any excess fluid with a fresh
lens tissue. Oily fingerprints and smudges may be removed
using this method. Use caution; rubbing too hard may scratch
the lens. On larger lenses, clean only a small area at a time,
using a fresh lens tissue on each area. Never reuse tissues.
Cleaning Mirrors
You should not have to clean the telescope’s mirrors very
often; normally once every few years or so. Covering the tele-
scope with the dust cover when it is not in use will prevent
dust from accumulating on the mirrors. Improper cleaning can
scratch mirror coatings, so the fewer times you have to clean
the mirrors, the better. Small specks of dust or flecks of paint
have virtually no adverse effect on the visual performance of
the telescope.
The large primary mirror and the elliptical secondary mirror of
your telescope are front-surface aluminized and over-coated
with hard silicon dioxide, which prevents the aluminum from
oxidizing. These coatings normally last through many years
of use before requiring re-coating (which is easily done).
To clean the secondary mirror, you will need to remove it from
the telescope. Before doing so, orient the telescope tube hori-
zontally so that nothing accidentally falls down and hits the
primary mirror. Hold the secondary mirror holder stationary
while loosening and removing the center Phillips-head screw.
Handle the mirror by its holder; do not touch the mirror surface
itself. Once the mirror (still in its holder) is removed from the
tube, follow the same procedure described below for cleaning
the primary mirror. You do not need to remove the secondary
mirror from its holder when cleaning.
To clean the primary mirror, you must carefully remove the
mirror cell from the telescope. To do this, remove the six
screws on the side of the tube near the primary mirror cell.
You do not need to remove the collimation screws on the bot-
tom of the mirror cell. Remove the mirror cell from the tube.
You will notice the primary mirror is held down with three clips
fastened by two screws each. Loosen the screws and remove
the clips.
You may now remove the mirror from the mirror cell. Do not
touch the surface of the mirror with your fingers; lift it carefully
by the edge. Set the mirror, aluminized face up, on a clean,
soft towel. Fill a clean sink free of abrasive cleanser with
room-temperature water, a few drops of liquid dishwashing
detergent, and if possible a capful of 100% isopropyl alco-
hol. Submerge the mirror (aluminized face up) in the water
and let it soak for a few minutes (or hours if it’s a very dirty
mirror). Wipe the mirror under water with clean cotton balls,
using extremely light pressure and stroking in a straight line
across the mirror. Use one ball for each wipe across the mir-
ror. Then rinse the mirror under a stream of lukewarm water.
Any particles on the surface can be swabbed gently with a
series of cotton balls, each used just one time. Dry the mirror
in a stream of air (a “blower bulb” works great), or remove any
stray drops of water with the corner of a paper towel. Water
will run off a clean surface. Cover the mirror surface with a tis-
sue, and leave the mirror in a warm area until it is completely
dry before reassembling the telescope.
7. Specifications
Primary mirror: 305mm diameter, 1500mm focal length, BK7
optical glass
Focal ratio: f/4.9
Focuser: Rack-and-pinion. accepts 2" and 1.25" eyepieces
with included adapter, collimatible
Optical tube material: Rolled steel
Eyepieces: 25mm & 10mm Sirius Plössls, multi-coated,
1.25" barrel diameter
Eyepiece magnifications: 60x (25mm) and 150x (10mm)
Finder scope: 9x power, 50mm aperture, achromat,
cross-hair, 5° field of view
Finder scope bracket: Dovetail base, spring-loaded
X-Y alignment
Eyepiece rack: Holds three 1.25" eyepieces and one
2" eyepiece
Mirror coatings: Aluminum with SiO
2
overcoat
Minor axis of secondary mirror: 70mm
Optical tube weight: 50 lbs.
Base weight: 33 lbs.
Tube length: 58"
Tube outer diameter: 14"