While shopping for a camera lens, the very first question the majority of people have "Is it sharp?., However if you removed the lens cap 30 days down the road there are 50-50 odds you’ll discover dust plus one or two fingerprints on it. And if you don't find a dirty the lens, there is another 50-50 odds there is dust plus one or two fingerprints on their "protective filter," that was installed to keep fingerprints and dust off their new lens. And we're only talking about a DSLR camera.
Looking at a a point & shoot compact camera, the odds are even greater for fingerprints or dust on their lens because when the camera is turned off, the lens typically slips behind the little louver blades which protect the lens, plus hides the fact there are smudges and dust on the lens.
Checking out the lens on your camera for dust and fingerprints is something you need to do on a frequent basis, not only does this ensure you’re capturing the sharpest possible images, but also because dust or an alien fingerprint left to "mature" can create ever lasting damage to the coating on the lens. Making sure your lenses are clean is not exactly rocket science, although,
a task which should be carefully and thoughtfully done using the correct tools and techniques.
Fingerprints, smudges, and dust accumulating on your front lens element, or your lens filter are easy to see because they’re always visible. While smudges and dust on the front lens element can reduce contrast levels and sharpness, there are even greater sharpness and contrast losses when there is fingerprints, smudges or
dust on the back lens element because it's the one which ultimately projects your picture onto the sensor or film plane of the camera. If the rear lens is not clean, your images will not be as sharp as they would be.
The Right Equipment for Keeping your Lenses and Filters Clean
- Portable Air blower (Not compressed air!)
- Micro-fiber cloth or lens tissue
- Methyl alcohol (also known as wood or methanol alcohol)
The Right Method for Cleaning Your Lenses and Filters
Your lens' surfaces have special coatings engineered to maximize color saturation, contrast and color fidelity along with minimizing flare. These coatings are easily scratched, so, when cleaning a lens it is always good to keep it simple. If loose grit or
dust is the only issue, the best way of removing it is by gently brushing the lens surface using a brush of soft camel-hair or use a few pumps of air by using a bulb-type air blower. Stay away from compressed canned air and don't grind grit into your lens surface using a cleaning cloth.
Fingerprints and other smudges require somewhat more effort, although you must be as tender as feasible. Begin with some lens tissue (fold it, do not bunch it up) or a supple micro-fiber cloth, breathe onto your lens surface (do not ever dry-clean your lens) then softly wipe the surface of the lens using a circular motion. Repeat as required using a new lens tissue or an unsoiled part of your micro fiber cloth. If this does not work, try using a small amount of lens-cleaning fluid containing an alcohol base or methanol (wood alcohol) on your tissue or cloth and try once more by tenderly wiping the lens using a circular motion.
Do not ever apply lens-cleaning fluid or alcohol directly to your lens surface. This can potentially do harm to the lens coatings or damage the adhesives which keep the elements of the lens in place.
If you are out doing a shoot and must remove dust, fingerprints or smudges from your lens, and don't have a lens tissue or micro-fiber cloth available, then a t-shirt made of cotton or other cotton-based material (the older the better, however without fresh starch) should take care the job just as well. Do not ever use paper towels, facial tissue, materials with a polyester-base, or any other coarse paper surface or abrasive fabric.
If you use the procedures above and they do work for you, or if there are gritty particles embedded into the smudge, which might scratch your lens coatings you’d be better off to let a qualified technician solve the issue.
If you observe a few particles of dust floating within the inner elements of your lens, they are not worth fretting about, as they will only have slight if any visible consequences on your images sharpness levels, and are not worth the trouble, time, or cost of taking the lens apart, cleaning it and reassembling
Dust on your Camera's Mirror or Imaging Sensor
A widespread misconception regarding dust is that it can seen in the viewfinder of your camera. The facts are is those dust specs you can see using your viewfinder aren't on your lens or image sensor, but on the mirror of your camera. These dust particles, as annoying as they are, have no affect your image quality. So before you remove your lens and attempt to clean your camera's mirror, note that the mirror inside your camera features a mirror with a surface-coat, which may be scratched permanently with barely any exertion on your part. Do not ever attempt to blast the dust away using compressed air, as you will most likely scratch, scar or pit this mirrored coating, or worse, blow the mirror from its hinges completely.
The most far-reaching action you should ever do is to remove these dust particles using a bulb air blower to gently blow them off. If are
unsuccessful at this, take your camera to a skilled technician or simply out up with as mentioned above, dust on a mirror is annoying, however does not affect your image quality.
If you see dust blotches on your picture files, in particular, blurry smudge-like blotches which repeatedly appear on the exact same places on all your image files are brought about by dust particles on your camera's imaging sensor. Again, the most far reaching but least invasive steps you should take on yourself is remove your lens, place your camera in it's mirror-lock position, then gently blow any dust off using a bulb air blower as you hold the camera with it's face down. If you are
unsuccessful doing this, I suggest that you take your camera to a skilled technician to clean the image sensor. You should never blow your mirror using compressed air, and the same thing goes for your camera's imaging sensor.
Dec 9, 2011