Instruction manual

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10.2.1 Cleaning the Lens
The best way to ensure a clean lens is not to let it get dirty in the first place!
Always keep a lens cover over the lens, and use the lens cap when the camera is
not in use.
Read your camera’s User Manual! Many recommend that you do not try to
clean the lens but instead take it to a dealer or other professional.
Most lenses are coated with a micro-thin anti-reflection coating. Although
lens coatings are resilient, they are still relatively easy to permanently scratch.
Once a lens is badly scratched, its sharpness is diminished and the image
contrast is reduced. A scratched lens is quite costly to repair; in fact, it's generally
less expensive to replace the lens than to try to repair it.
Each time the lens is cleaned there is the risk of tiny abrasive particles
present in the tissue, creating microscopic scratches in the coating. For this
reason a lens should not be routinely cleaned (the way you regularly wash your
hands, for example); a lens should only be cleaned when you see dirt or dust on
the lens surface.
Small quantities of dust on a lens will not appreciably affect image quality, but
fingerprints or oily smudges are a different matter. If not promptly removed, the
acids in fingerprints can permanently etch themselves into a lens coating.
And believe it or not, there is a right way and a wrong way to clean a lens.
Clean it correctly and you’ll maintain peak optical performance; clean it the wrong
way and you could scratch the lens.
a. Carefully blow off any dust or dirt, using a blower brush or (very carefully!)
compressed air. If you use a brush, do not let the fine bristles of the
brush touch your hand or fingers; oil from your skin will be transferred to
the bristles and then smeared on the lens.
b. Dampen a lens tissue with lens cleaner and very gently rub the lens in a
circular motion. While very gently rubbing, turn or roll the tissue slightly
so that any dirt will not be rubbed over the lens surface. [Note: Never drip
lens cleaner directly on a lens; it can easily seep behind lens elements
and create a major problem.]
c. Gently wipe the lens surface from the edges toward the center of the lens,
with a lifting rather than rubbing action. A micro-fiber cleaning cloth is a
good alternative to lens tissue and requires no lens-cleaning fluid. Do not
reuse cleaning tissue, and keep any micro-fiber cleaning cloths in their
original containers to keep them clean. Micro-fiber cloths are washable
and can be tossed in with your laundry periodically. [Don't clean a lens
with silicon-treated lens tissues or the silicon-impregnated cloths
commonly sold for cleaning eyeglasses as the residue may permanently
discolor the coating. And don’t use a cotton T-shirt or other fabric, which
may have embedded grit in the material.]
10.2.2 Condensation
Condensation or raindrops on the lens can distort or even totally obscure an
image. When a camera is taken from a cool area into warm air, the lens