Dust is amazing stuff. It collects in vast space nebulas and gloms together to form planets and ignite stars. In the atmosphere, it scatters sunlight to spark stunning sunsets. But let's face it, dust's true superpower lies in its ability to get into everything, including the expensive cameras with which we take pictures of -- well, stars and sunsets, among other things.
Dirt is fine on a desert trail or forest track but, in your optical path -- the path light traces through your camera -- it can spoil your whole shoot. When that happens, it takes more than a few puffs of air to put the snap back in your shots.
The question is, where to begin? Do those specks, splotches and scratches stem from a dusty sensor or from dirt on your viewfinder, mirror or lens? To find out, head to a well-lit space and take several photos of, say, a blank white sheet of paper. Increase your f-stop and set the camera to aperture-priority mode so that it automatically sets the appropriate shutter speed. Now upload your pics to a computer and zoom to a 1:1 pixel ratio (one photo pixel per screen pixel) [sources: McHugh; Stern].
If you see small, translucent spots, dark specks or thin lines that recur across photos, it's a good bet that cloth fiber, hair, pollen or dust have gotten somewhere they don't belong. To diagnose where, try fiddling with the f-stop and snapping more shots. If the dirt is located on the sensor, you'll see a change in the dots' size and clarity; if you don't, then you probably have dirt on the on the viewfinder focusing screen or the single-lens reflex (SLR) mirror. Lens shmutz is harder to diagnose, since it won't always show up on photos. Switch lenses and see if you notice a difference [sources: McHugh; Stern].
Digital SLR cameras are especially susceptible to dust because they rely on a sensor that is exposed to air every time you change lenses. The most obvious signs of a dusty sensor are loss of contrast and/or small, diffuse dots cropping up in your photos. Why are the dots so fuzzy? The specks don't actually sit on the camera sensor's photosites -- the individual light detectors populating your charge-coupled device (CCD) or complementary metal–oxide–semiconductor (CMOS) sensor. Instead, they deposit on the topmost surface of whatever stack of filters covers the sensor, which can include an anti-aliasing filter, antireflective coatings, microlenses and/or an infrared filter. That's why increasing your f-stop -- which diminishes your aperture and increases your depth of field -- casts them into sharper focus [sources: McHugh; Stern].
Unfortunately, when it comes to sensors, identifying the problem is the least of your worries.
Sensor-ship I: Scratching the Surface (Without Scratching the Surface)
Getting a sensor clean is tricky business. Without patience, care and dexterity, you risk making matters worse, either by pulling in external crud, like camera lubricants and ambient dust, or by gouging costly scratches into the surface [sources: Breen; McHugh]. If you make a shambles of it, you could void your warranty. Your safest bet? Send your camera off to the manufacturer or drop it at a camera shop -- one that insures against damage caused by its staff.
Cleaning services charge in the range of $30-$50, which will dent your wallet less than the individual tools you need for doing the job yourself but will leave you sans camera for a few weeks [source: Atkins; Breen]. If that doesn't work for you, or if you're a dyed-in-the-wool DIY-er, you have your choice of gadgets, which we'll dive into in the next section.
A few more caveats: When cleaning your sensor, plug the camera into an outlet or, lacking an AC adaptor, charge your batteries fully. If your camera's battery dies before you have finished cleaning, the mirror might shut and, with your hand or cleaning tool in the way, you could damage the mirror or scratch the sensor [sources: Breen; McHugh; Stern].
Also, it's a good idea to clean the camera body, lens and lens mounts with a damp cloth before you start so that no crud from the camera ends up on the parts you're trying to clean. Think of it as sweeping before you mop. Some camera cleaning kits include swabs and a solution for washing the interior chamber -- another good first step [source: McHugh; Stern].
Some cameras feature a self-cleaning mode, which makes for a handy gizmo but is not a true cleaner. Speaking of preventative maintenance, here are a few tips for saving your sensor: Keep your lenses and chamber capped, protect your lens with a hood and filter and switch lenses as quickly and cleanly as you can. If possible, point your camera down when switching lenses. To avoid fungus, keep your equipment moisture-free and consider storing it with a drying agent, or desiccant, such as silica gel [source: Kelly]. Also, stop carrying your photo rig in your gym bag.
Whatever else you do, consult your owner's manual before tackling any cleaning or maintenance. If your manual offers little on the topic of cleaning, track down a good third-party book that covers your model. Then you'll be ready to break out the tools and start cleaning.
Sensor-ship II: Coming to Your Sensors
OK, so you're really confident in your abilities, you're stuck in the field somewhere and have no choice, or you live for danger. Whatever the reason, you've dismissed our warnings and are going for Operation: Sensor Sweep.
Begin by activating your camera's cleaning mode. This will flip up the mirror and reveal the sensor. Check that you have plenty of juice, either from a full battery or a wall socket. Once you have the lens off and can see the sensor, you can optionally use a special loupe, or small magnifying tool, to spot the dust [source: Cameta Camera].
Shops hawk a befuddling array of sensor-cleaning schlock, much of it packaged in kits. Not all utensils are created equal, and many kits amount to expensive overkill, so we've listed the main tools below, from least invasive to direct-but-demanding.
A sensor blower is a plastic squeeze bulb with a nozzle that blows away loose dust with a puff of air. Because it never touches the surface, it is the least risky tool and the easiest one to use in the field. Unfortunately, blowing might not be enough to knock dust loose, and blown dust can redeposit (pointing the camera at the ground helps) [sources: Kelly; McHugh]. Do not use a blower that has a brush, which can retain dust and scratch the sensor covering [source: Breen]. Also avoid compressed air, which pumps out too much force and can deposit damaging chemicals [sources: Atkins; Nakoma Products; Kelly].
A sensor brush or sweep looks like a fine, flat paintbrush. Use a very light touch, starting at one end of the sensor and gliding smoothly across. Remember, you aren't scrubbing or even sweeping; rather, you're allowing the electrostatic action of the bristles to attract the dust, like a charged amber rod attracts a balloon. Clean the brush between sweeps, and don't let the brush's edges drift off the sensor or you might pick up other pollutants. All in all, a sensor brush or sweep is a good compromise tool and is handy for dusting your focusing screen [sources: Breen; Kelly; McHugh].
A sensor stamp or pen has a deformable tip (usually made of silicone) that hugs individual dust particles. To use, simply press it against the surface of your sensor and watch the dirty lovefest begin. Because you press instead of dragging, you're less likely to cause unwanted scratches. Avoid the versions that use adhesives, which can leave sticky residue behind [source: McHugh].
A sensor swab, wipe or wand squeegees your sensor using a small, flat-edged paddle wrapped in a lint-free tissue. The tissue is treated with cleaning fluid and will handle just about anything, but using it requires the most care. Again, start at one side of the sensor and drag across, applying no more pressure than you would with a fountain pen. Optionally, you can then twist the swab 180 degrees and drag the clean side back across. As with any fluid, check with the manufacturer and make sure you have the right one for your camera. Also, make sure your paddle width matches your sensor size [sources: Chriss; Kelly; McHugh; Stern].
Other tools include sensor stain removal solution, sensor brush washers and brush-cleaning devices, but shutterbugs disagree regarding their usefulness and value, especially given their often steep price tags [sources: Breen; Chriss].
Now that you've swabbed the sensor, you can look at your lenses.
Lens Contacts and Mirror Objectives
Like the shielding layers on sensors and filters, lens coatings scratch easily, so tread lightly when giving them the old spit-and-polish. In fact, go ahead and avoid both spit and polish. Start instead with a few blower puffs on both the interior and exterior lens, followed by some light sweeps with a soft camel-hair brush. And again, never blast your lenses with compressed air, which can leave behind damaging chemicals [sources: Delaney; Kelly; Stern; Weitz].
Leave cloths and papers out of it until you clear the area of dust, or you risk grinding grit into the lens, after which you'll dream of the halcyon days when smudges were your worst concern. If you decide to use a cleaner, don't go for over-the-counter options; instead buy one designed for your camera and lenses; otherwise, you might -- you guessed it -- damage the coating [sources: Delaney; Kelly; Stern; Weitz].
Removing smudges or fingerprints requires a delicate touch. Breathe lightly onto the lens to add a modicum of moisture, then take a microfiber cloth or lens paper -- folded, never scrunched up -- and wipe in gentle, circular motions [sources: Delaney; Kelly; Weitz]. Remember how, when you were a little kid, your mom would lick a napkin and scrub your face with it? That's exactly what you shouldn't do.
Out in the field without your gear? An old cotton T-shirt will do in a pinch, but never use a fabric or tissue with a rough texture, such as polyester rags, paper towels or facial tissue [source: Weitz]. Nikon's Lens Pen offers another option: One end has a dry brush for whisking away specks, while the other sports a soft round chamois tip with a non-liquid lens cleaner [source: Kelly].
As for cleaning the mirror ... don't. Just don't. Leave it alone. At most, give it a few puffs of air from your lens blower, but never touch it. The mirror's surface coating takes scratches like an iPhone in a blender, so either live with it or have a pro service it [source: Weitz].
Finally, if you're concerned about the camera shell, a wipe-down with a damp cloth will usually do the trick. Lens blowers are handy for blasting dirt out of nooks and crannies. In some cases, you might need to treat certain parts, such as leather straps, with extra care [source: Delaney].
Photographers cover a broad spectrum of personality types, from thrill-seekers and adventurers to more subdued shutterbugs, and I found this range reflected in the advice I came across while researching this article. Some shouted from the mountaintops, "In the name of all that's holy, man, turn back!" whereas others just shrugged dismissively, chopped a kitchen spatula in half, wrapped it in tissue and set to work.
If it takes a certain daring -- or is it disregard? -- to crack the case on your computer and blow it free of dust, then it takes even more to tackle cleaning a digital camera sensor. It strikes me as a lot of risk to take to save a few bucks, but I suppose, like many things in life, it comes down to how risk-averse you are; and, of course, there's always the heady sense of accomplishment that comes with doing something yourself.
- Atkins, Bob. "Cleaning Digital Sensors. Bob Adkins Photography." May 24, 2008. (June 16, 2012) http://www.bobatkins.com/photography/tutorials/sensorclean.html
- Breen, Christopher. "Cleaning Your Digital Camera Sensor." Macworld. March 7, 2006. (June 16, 2012) http://www.macworld.com/article/1049711/sensorclean.html
- Cameta Camera. "Lenspen SensorKlear Digital SLR Camera Sensor Cleaning Kit with Wand, Blower & LED Loupe." (June 16, 2012) http://www.cameta.com/Lenspen-SensorKlear-Digital-SLR-Camera-Sensor-Cleaning-Kit-with-Wand-Blower-LED-Loupe-56665.cfm?utm_source=googlebase&utm_medium=base
- Chriss, Dean. "Image Sensor Cleaning." Dean M. Chriss Photography. Feb. 9, 2012. (June 16, 2012) http://www.dmcphoto.com/Articles/SensorBrushes/
- DeLaney, Chuck. "Summertime Tune-up for Your Camera." New York Institute of Photography. (June 16, 2012) http://www.nyip.com/ezine/techtips/tuneup.html
- Kelly, Heather. "How to Clean a Digital Camera." Macworld. Aug. 17, 2010. (June 16, 2012) http://www.macworld.com/article/1153367/cleancamera.html
- McHugh, Sean. "Camera Sensor Cleaning." Cambridge in Color. (June 16, 2012) http://www.cambridgeincolour.com/tutorials/camera-sensor-cleaning.htm
- Nakoma Products. Endust Compressed Air label.
- Stern, Zack. "Clean Your Digital SLR Camera's Image Sensor." PC World. March 25, 2008. (June 16, 2012) http://www.pcworld.com/article/143656/clean_your_digital_slr_cameras_image_sensor.html
- Weitz, Allan. "How to Clean Your Lens and Filters Properly." B & H Foto & Electronics Corp. Jan. 10, 2011. (June 16, 2012) http://www.bhphotovideo.com/indepth/photography/tips-solutions/how-clean-your-lens-and-filters-properly