PART IX. CARE OF OPTICS AND CLEANING
The easiest way to clean eyepieces is with Q-Tips and a good lens cleaner.
In the absence of a good lens cleaner product, pure isopropyl alcohol
(available at most pharmacies, and diluted to 70% is OK) can be used.
First, use a blower bulb (like an ear syringe) or a can of compressed
air to blow off all dust visible on the lens surface.
Then, put a drop of cleaning fluid on the Q-Tip. Never put the fluid
directly on the lens, as this will inevitably result in too much fluid
being applied, and excess fluid can easily wick around the edges of eyepiece
lenses and get in between them. Then, using "daisy petal" motions (oval
motions traveling from edge of lens to just past the center), turn the
eyepiece under the moving Q-Tip until the entire surface is cleaned.
Immediately turn the Q-Tip around and repeat the action, mopping up the
fluid and dirt as you go.
After a couple passes, replace this Q-Tip with a clean one and continue
until all the fluid and/or haze on the lens surface is gone. When you
examine the eyepiece lens at a low angle in bright light, there should
be no haze, streaks, grease, or oils visible. If the eyepiece lens is
very dirty, you may need to repeat this to completely clean the lens.
The eyepiece lens closest to the eye (called the Eye Lens) is usually
the one that gets dirty. The lens farthest away from the eye (called the
Field Lens) rarely gets dirty.
To keep your eyepieces clean when not in use, keep them capped at both
ends, even when in a case.
CLEANING LARGER LENSES
To clean the surface of a large objective lens, or the corrector plate
of a Schmidt-Cassegrain or Maksutov-Cassegrain telescope, the eyepiece
technique needs only to be modified a bit:
Clean the lens in small sections (say 2-4 square inches) at a time, using
sterile cotton balls or wipes (be CERTAIN these have no additives or lotion
on them), and proceed around the lens until the whole surface is done.
Use the same procedure as the eyepiece cleaning to verify you have completely
cleaned the lens surface.
CLEANING THE MIRRORS IN A REFLECTOR TELESCOPE
First, remember this: CLEAN A MIRROR ONLY WHEN YOU HAVE TO. Those aluminized
surfaces are deposited directly on the glass-there is no layer of glass
on top of them-so they are delicate and easily damaged.
What follows is the simplest technique to clean the mirror, and will
result in no damage to the optical surface. NEVER use Windex. NEVER wipe
the mirror when dry.
Blow the dust off and hold the mirror at a low angle under gently-running
tap water to get the surface dust off (note: no brushes!!!). Then, immerse
in a rubber/plastic pan with enough distilled water in it to cover the
mirror. Always use distilled water to prevent chemical reaction with the
mirror coatings. IF the mirror was stained (not just dust) from dampness
cementing pollen onto its surface, ONE drop of dishwashing detergent (the
basic kind without any additives like hand lotion) in the plastic pan
(one drop to 2 or more gallons, and allowed to sit until no visible foam
is there) will help soak the mirror stains away. After letting it sit
for 10-20 minutes, swirl the water over the mirror by moving the mirror
around. Did all the stuff blow off the mirror? Then move to a rinse. Is
the stuff still there? Then use sterile cotton balls from the pharmacy
to *gently* drag across the mirror surface, using one ball per swipe (do
not make two swipes with one ball) until clean.
Use tap water to rinse all water off the mirror (or alcohol/water mix
in a sprayer), and dip the mirror into a second pan with distilled water
without any soap added. Swirl the water around to get anything left on
the mirror surface off.
Remove the mirror from the pan on its edge, letting the surface tension
of the water pull all the drops down. Removing the mirror from the water
slowly helps in this regard. Stand the mirror on its edge and use the
corners of pieces of paper towel (brown ones are better for the environment--there
is no residue of dioxin used to bleach the paper) to absorb any drops
left on the mirror. The mirror should appear quite clean. Leave vertical
until the back of the mirror is completely dry, then replace the mirror
in the scope. If the mirror is being re-glued, cover the mirror so dust
won't accumulate and let dry a few more hours before attempting to re-glue.