Orion #9781 EON 72MM Care & Maintenance, Specifications, Cleaning Optical Surfaces

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

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