Orion #9781 EON 72MM - Manual (Page 7)

7
Care & Maintenance
Give your telescope reasonable care and it will last a lifetime.
When not in use, keep its dust cover on as well as the dust
cap on the eyepiece opening. Keep the telescope inside the
hard storage carrying case when not in use. Store it indoors
or in a dry garage. Do not leave the telescope outside except
when using it. The optical tube is aluminum and has a smooth
anodized surface that should resist scratches and smudges.
If a scratch does appear on the tube, it will not harm the tele-
scope. Smudges on the tube can be wiped off with standard
household cleaners.
Dew
When you are ready to pack up your telescope at the end of
the night, avoid immediately storing it in the hard case if you
encountered heavy dew and the telescope is damp. Instead,
bring the telescope inside and allow the moisture on the tele-
scope to evaporate. If dew forms on the objective lens, then
leave the dust cover off of the telescope until all the moisture
has evaporated. Once the telescope has completely dried out,
place it in the hard case.
Cleaning optical Surfaces
In general, your telescope will only need to be cleaned on a
very minimal basis. Dust particles on the objective lens do not
effect the optical quality of your EON. Loose dust can simply
be blown off with air, using a compressed air can or blower
bulb (available from Orion). Any remaining dust is best left
alone, unless the build up is extreme. Finger prints and water
marks should be cleaned from your telescope’s objective
lens. Any quality optical lens tissue and cleaning fluid spe-
cifically designed for multi-coated optics can be used to clean
the telescope’s objective lens as well as the lenses of your
eyepieces and finder 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, or lightly brush the
lens with a soft camel hair brush. 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! Clean only a small area at a time, using a fresh lens
tissue on each area. Never reuse tissues.
Specifications
Eon 72mm ED apochromatic refractor
Optical tube:
Seamless aluminum
Objective lens: Apochromatic, rear element made
of FPL-51 ED glass, air-spaced
Objective lens coating: Fully multi-coated
Lens cell: Machined aluminum
Focal length: 430mm
Focal ratio: f/6.0
Baffles: 2 knife-edge baffles
Focuser: Dual Speed 11:1 Crayford, accepts
1.25" or 2" accessories, brass
compression ring
Mounting: Mounting block, dovetail design,
1/4"-20 threaded
Weight: 5.0 lbs./2.27 kg
Length: 12.5"/31.75cm with dew shield
retracted
Outside Diameter: 3.43"/87mm
Eon 80mm ED apochromatic refractor
Optical tube:
Seamless aluminum
Objective lens: Apochromatic, rear element made
of FPL-53 ED glass, air-spaced
Objective lens coating: Fully multi-coated
Lens cell: Machined aluminum
Focal length: 500mm
Focal ratio: f/6.25
Baffles: Cone baffle
Focuser: Dual Speed 11:1 Crayford, accepts
1.25" or 2" accessories, brass
compression ring
Mounting: Mounting block, dovetail design,
1/4"-20 threaded
Weight: 6.5 lbs./2.95 kg
Length: 15.25"/38.74cm with dew shield
retracted
Outside Diameter: 3.54"/90mm
Eon 120mm ED apochromatic refractor
Optical tube:
Seamless aluminum
Objective lens: Apochromatic, rear element made
of FPL-53 ED glass, air-spaced
Objective lens coating: Fully multi-coated
Lens cell: Machined aluminum
Focal length: 900mm
Focal ratio: f/7.5
Baffles: 3 knife-edge baffles
Focuser: Dual Speed 11:1 Crayford, accepts
1.25" or 2" accessories, brass
compression ring
Mounting: Tube rings and dovetail plate
Weight: 14.31 lbs./6.49 kg
Length: 31.25"/79.38cm with dew shield
retracted
Outside Diameter: 3.54"/122mm