Tuesday, June 19, 2007
The Enemy Within - Defeating Dust
Dust is a serious issue for digital shooters. If you have persistent dust spots on your image sensor, it might be time to consider that your gear bag could be the culprit.
Most photographers have never cleaned a camera bag. Basically, you're looking to get rid of dust and other small contaminants. A quick once-over with a vacuum, taking special care to get into cracks and corners, will do a good job of eradicating most of the problem.
One area where digital cameras have made life for pros more difficult is keeping the image sensor clean. If you're shooting film and there's dust inside your camera that happens to settle on the film, you'll undoubtedly end up with a spot or two to fix later, but it will be confined to a single frame since you'll advance the dust along with the film when you wind.
What about the digital image sensor? If you're unfortunate enough to have dust in your digital camera and it lands on the sensor (more accurately, the filter above the sensor), that speck of dust will show up on each and every frame that you shoot until it's cleaned off. Imagine—hopefully you'll only be imagining—the possibility of shooting hundreds of frames only to have to retouch each and every one to clear them of all that dust. Then imagine that instead of one speck of dust, which is bad enough, you have 10 or 20 specks on every frame!
Keeping the image sensor free of dust usually isn't a big deal for photographers who are confined to a studio. For anyone who takes a camera out on location, though, it quickly can escalate from an annoyance to a serious issue. Practicing preventative maintenance is the first line of defense against this menace to the imaging society. That means taking care to remove your lenses in a sheltered environment whenever possible, getting the new lens on the camera quickly, not allowing the body to sit lens-less for any period of time, and brushing the body before you take off the lens to remove any particles that could fall into the camera.
All of these precautions will help to keep the dust at bay. If you're practicing good camera hygiene, but you're still ending up with dust on the image sensor, maybe it's time to look at a different culprit.
Your camera bag, which you bought to protect all of your gear from impact and the elements, conceivably could have turned against you. David Sparer, professional tech rep for Canon, advises, “I tell photographers to clean their bags or cases regularly. I find that the bag can eventually come to harbor more dust than they keep out.”
Even when you're careful, the inside of the bag eventually will become dirty. The interior compartments of most bags are constructed of a material that doesn't show contamination obviously so you can't always trust that you'll see if your bag is a source of dust rather than a shield from it.
A good plan is to follow a regular cleaning schedule. Most photographers have never cleaned a camera bag. Basically, you're looking to get rid of dust and other small contaminants. A quick once-over with a vacuum, taking special care to get into cracks and corners, will do a good job of eradicating most of the problem.
If you have a more significant dirt issue that a vacuum won't solve, it's time to go for heavier cleaning. Maury Cohen, product specialist at Lowepro USA, says, “We suggest that customers hand-wash the bag with a mild, non-abrasive, non-solvent detergent like Ivory, then rinse thoroughly and drip dry.” Once cleaned, the bag should be contaminant-free.
Eventually, even vacuuming and washing won't be enough. If you find that, despite using the careful lens-changing technique, you continue to get fresh dust spots on your sensor, it's time to consider replacing the bag.
Says Sparer, “I see lots of photographers who have old bags that are way beyond their useful life. The photographer tends to hang onto the bag for sentimental reasons or because it's sort of a badge of honor, but the fact is, the bag is probably causing all sorts of dust spots on the sensor. It's time to replace it with a new one.”
Bag manufacturers such as Lowepro and Tamrac take great pride in the design and construction of their gear—the bags are designed to last a lifetime. By keeping the interior clean and contaminant-free, you can expect that your bag will not only protect your gear from exterior hazards, but also from the dust enemy within.