KEEPING OPTICS SPARKLING
Nothing can smear your view of stars and planets better than an eyepiece coated with dust, eyel'ash oil, and fingerprints. To clean an eyepiece, first blow off loose dust with a lens blower. Then lightly moisten a Q-tip cotton swab with camera-lens cleaning fluid.
Wipe the lens gently with the wet swab, then again with a dry one to remove the streaks. Never pour the fluid, directly onto the lens— it can seep into the eyepiece, staining interior lenses. And do not try to disassemble an -eyepiece—the lenses could all tumble out.
The main lenses and mirrors of telescopes should be cleaned with caution and as seldom as possible. To clean refractor lenses, blow off as much dust as you can, then moisten lens cleaning tissue with lens cleaning fluid. Wipe the lens with gentle strokes. Do not rub hard.
Reflecting mirrors are the most delicate of all. They must be cleaned only with gentle swipes of cotton balls moistened with a solution of distilled water and mild detergent, then rinsed with pure distilled. Other methods can far more harm than dust. To keep the dust off in the first place, never store telescopes with their lenses or mirrors exposed.