Wiping raindrops from the front element with their shirttails is all many videographers do to keep their lenses clean. But it takes more than an occasional wipe to ensure maximum performance from any camera's optical system. Performed regularly, the following simple steps are all it takes to ensure consistently sharp, spotless images.
Since it's always right out there, the front of the lens gets the most abuse, both from the environment and from abusive videographers. Always protect the front element with a clear screw-in filter and protect the filter by wiping it only with a soft lintless cloth, lens paper, or, better still, that small piece of ultra-soft chamois leather that you carry in your "fanny pack." Wipe with a side-to-side motion, not circular, and use liquid cleaner sparingly; the moisture in your breath is often enough to loosen debris stuck to the glass. For stubborn spots--such as fingerprints or winter road salt splatter--use only liquid lens cleaners formulated for optical glass and apply the cleaner to the chamois or lens paper, not directly to the lens.
Once the forward-facing glass is clean, focus on removing dust from less exposed optical surfaces. For this you'll need a fine brush, preferably made with camel hair. A temporary brush can be created out of lens paper. Roll a single sheet into a moderately tight tube, tear it across the middle, and use the soft jagged ends of the torn portion to form a brush. Sweep dust particles--again with a side-to-side motion--off the back of the clear filter as well as from the front element itself.
