The most important part of a camera, and the most vulnerable to dirt and damage, is of course the lens. Its exposed position stuck out on the front of the camera makes it prone to finger smears, dust and even scratches, any of which will seriously degrade the quality of your photographs, so itâ€™s important to know how to clean and protect it.
If your lens gets dirty, the first step is to carefully remove any dust. Dust particles can consist of many things, from the flakes of human skin and hair that reportedly make up a significant percentage of household dust, to tiny particles of sand that might get picked up at the beach. Unfortunately many types of dust are highly abrasive, and simply wiping dust from the lens with a cloth can leave tiny permanent scratches on the surface of the lens. These build up over time, and will eventually ruin your lens.
The best way to remove dust is by blowing it off. Don't just blow on the lens with your mouth. Water vapour and even particles of saliva in your breath can cause some of the dust to stick to the lens, where it will cause the scratches mentioned above. Instead itâ€™s best to use either a can of compressed air, usually know as an â€œAir Dusterâ€, or a good bellows-type blower such as the popular Giottos Rocket brand, either of which should be available from any good camera retailer. Do not use other compressed gases or any aerosol with a liquid propellant, as the former may damage your health and the latter may damage your camera.
You can also use a soft brush, either a specialist lens brush or a soft-bristled model makerâ€™s paint brush, to remove light dust from the lens, but be sure to keep your brush clean and replace it regularly, because dust and grit can build up between the bristles.
Once youâ€™ve blown any dust away, wipe the lens gently with a soft lint-free cloth. The best type to use are specialist micro-fibre lens cloths, again available from any good camera shop. At a push a clean handkerchief will do, but do not use paper, not even tissue paper. Paper contains tiny abrasive fibres which will leave minute scratches on your lens. As with dust scratches these may not be apparent at once, but will build up over time and ruin your lens.
Another good alternative is the Hama LensPen, a very useful device that combines a good retractable lens cleaning brush and a soft wiping pad impregnated with an anti-static lens cleaning fluid. They are inexpensive and convenient, and itâ€™s a good idea to get one and keep it in your pocket when you go out shooting. There are small size LensPens available that are ideal for cleaning the smaller lenses of compact cameras.
Alcohol-based or detergent-based cleaning fluids can be used, but only use those designed specifically for cleaning optical glass. Do not use household cleaning fluids, as these often contain abrasives. They may be great for removing burnt-on grime from your ovenware, but theyâ€™ll cause irreparable damage to your lens.
If you do use a cleaning fluid, apply it to the cleaning cloth, not directly to the lens. If you let liquid pool on the lens it may seep in around the edges of the lens mounting and get inside the lens barrel, where it can leave marks on the interior elements of the lens, and possibly encourage the growth of fungal blooms on lens surfaces. Wipe from side to side, so that youâ€™re wiping the dirt off the lens, not just pushing it round in circles.