Defeating Dust :: Digital Photo Secrets

Defeating Dust

by David Peterson 0 comments

OK, so I know that dust is not sentient, but sometimes it really does feel like it’s out to get me. It shows up all over my house, totally uninvited, regardless of whether or not I keep my windows closed. It makes me sneeze and it seems to have a magnetic attraction to my car, especially in those first moments after I’ve washed it. And no matter how careful I am, it always seems to work its way into my camera. Can anything stop the great dust menace?

[ Top image Through The Dust by Flickr user MohammeD BuQuRais]

The answer, thankfully, is yes. Here’s the thing about dust—it really is literally attracted to your camera’s sensor. And it’s everywhere, so no matter where you go in the world, if you have to change lenses then dust is going to settle inside your camera. And as soon as you switch your camera on, those little particles jump right onto your sensor—in fact the charged surface attracts those specs of dust just like metal attracts a magnet. So it’s almost like you’re doomed to fill your camera up with dirt no matter what you do.

If you really hate dust, the best way to defeat it is to not own a DSLR. Any other camera—provided it has a fixed lens—is going to be more or less safe from those invading forces. But the thing is, you probably do want to hang onto your DSLR. You’ve grown attached to it, and let’s face it, you invested a lot of money in it. For the most part, it takes better photos than that old point and shoot you probably still have in a drawer somewhere, and you’d really like to avoid going backwards. So the bad news is, if you like your DSLR you’re eventually going to have to figure out how to deal with all that dust.

  • Canon EOS 350D Digital
  • 100
  • f/36.0
  • 0.033 sec (1/30)
  • 120 mm

Dirty by Flickr user Håkan Dahlström

Preventing dust

You have almost certainly heard the term “prevention is the best medicine,” more than likely coming out of your doctor’s mouth when she was scolding you for things like eating junk food or not exercising enough. But the same advice holds true for a lot of things in your life, and keeping dust out of your camera is one of them. So the first thing that you can do to deal with the great dust menace is this: don’t change your lens in a dusty environment. If you’re going to be shooting a herd of cattle on a dusty lot, for example, it’s a very good idea to pick a lens and stick with it. If you want wide shots, put a wide angle lens on your camera before you leave the house and don’t take it off again until you get home. If you want long shots, do the same—and try to make peace with the fact that you’re just not going to get a lot of wide shots that day. If you must change lenses, find a secluded indoor location where you can do that. And keep note that your car, if you parked it close to that dusty lot, may not be the right place either—dust will get into the car as you open up the doors and potentially swirl around inside, unseen and ready to pounce the moment you open up your camera.

  • Sony SLT-A65V
  • 100
  • f/8.0
  • 0.1 sec (1/10)
  • 16 mm

My Sandy Sigma Lens by Flickr user fran.trudeau

Even when you are in what seems like a dust free location, remember that there is really no such thing. Dust exists no matter where you go, and most of the time you aren’t going to see it. So even when you think you’re in the clear make sure that you switch off your camera before you change lenses. When your camera is on, the sensor is charged—which means it’s a dust magnet. So turn off your camera first, then change the lens.

Think about where the dust is likely to be and try to angle your camera in such a way that the majority of it will bypass your camera’s sensor. Angling your camera so the sensor is pointed down, for example, will stop airborne dust from falling on it. Do the same with your lens—the part that attaches to the camera is also prone to attracting dust so keep it pointed down. And think about where the wind is coming from—try to place your body between the wind and your camera to minimize the amount of dust that actually reaches your camera’s sensor.

Oh no, despite all my efforts …

Don’t worry, no matter how hard you try you’re still going to get dust on your camera’s sensor, so its sudden appearance on your photographs is not always because you did something wrong. Remember that dust is really small, mostly invisible, and ultimately you can only do so much to discourage it. So once it’s there, you can do a couple of things.

  • Nikon D70s
  • 1250
  • f/11.0
  • 0.7
  • 37.8 mm

Dirty Sensor by Flickr user Wanna Be Creative

Many modern DSLRs have a sensor cleaning feature, which is really just a mode that physically shakes the dust off of your camera’s sensor. You can engage this setting manually whenever it occurs to you, or (on some cameras) you can set up the feature to activate whenever you switch the camera on or off. I’ve personally found this feature to be sort of moderately useful—it does get rid of dust, but there are often stubborn bits of lint or other particles that seem particularly resilient and won’t vacate the sensor no matter how many times I engage the cleaning function.

Another thing you could do is just live with the dust. Now, I know this sounds crazy but if you rarely shoot at small apertures (maybe landscapes and macro are not your thing) those little specs may not even show up in your photos. At large apertures the light will just wrap around those specs of dust, and they won’t even show up in your photos. At small apertures, however, they’ll come into focus just like all those other elements in a scene will, so you’ll have a tack sharp mountain range, some tack sharp trees in the foreground, and a tack sharp glob of lint in the sky. You probably will notice dust less in certain types of photos, too—say you shoot mostly street photos, and they typically include a lot of textured surfaces and you hardly ever have any sky in the scene—you may not even notice those specs of dust because they’ll just blend in with everything else. So unless those specs of dust are actually having an impact on the photos you shoot, getting rid of them is not an emergency situation.


    Canon's Big Anti-Dust Technology Lie by Flickr user Thomas Hawk

    How camera manufacturers are trying to help us

    Fortunately, camera manufacturers are not oblivious to this problem. Most companies are actively working to come up with solutions to the problem of the great dust menace. These solutions range from extra surfaces built into the camera that give the dust an alternate place to settle (thus rendering it less visible in the final image) to anti-dust coatings, vibration cleaning before every shot and software mapping. And in case you’re curious, software mapping is exactly what it sounds like—you shoot a photo of a plain white surface, then your camera figures out where all the dust is and saves a “dust map” to internal memory. Then whenever you take a photo, the software clones all the dust particles out for you, so you don’t have to do it in post processing later on. Yes, I know—this is clearly a Band-aide solution, but if you don’t have the time to send your camera in for a cleaning before that once-in-a-lifetime African safari, it may mean the difference between a whole set of dirty photos and a whole set of clean ones.

    Speaking of post processing

    Dust specs are relatively simple to remove in post processing. The spot healing tool (the one that looks like a Band-aide) can remove dust specs one at a time with relatively little fuss—except that when there are a lot of these spots it can take just about forever to do a single photo (hint: do dust spec corrections at 100 percent magnification, or you’ll almost certainly miss something). Now imagine having to do this with every photo you shoot at a small aperture—yes, this could cause psychological damage. So if it gets to the point where you’re having to remove it in post-processing all the time, you really can’t keep avoiding the cause of the problem.

    Send it in

    This is my preferred way to deal with dust specs. I pick a few weeks on my calendar when I’m not going to die without my DSLR—when I’ve got no travel plans, no family events and no holidays or special occasions. I make peace with the fact that I’m going to shoot all my photos during that period of time with my old point-and-shoot camera, and I box up my DSLR and send it to the manufacturer for cleaning. Remember to insure your package and get tracking information, and for a pretty nominal fee your camera will come back to you spec free. Now, I typically do this once a year or so because I find that despite all of my best efforts to keep dust out of my camera, that’s about how long it takes for those dreaded specs to start appearing in the sky in numbers that I can’t easily cope with.

    Do it yourself

    If, however, you find that you just can’t bare the thought of being without your DSLR for that long, you can clean your sensor at home (though I don’t personally recommend it). One thing to keep in mind is that if you don’t do it right you can actually do more harm than good. You could scratch your sensor or you could introduce even more dust, and either one is not a good result.

    Start by using air—if you don’t physically touch your sensor, you’ve got a lot less potential for damage. Do not, however, use compressed air or CO2 because the liquid propellant can actually get inside your camera and cause damage. Instead, use a bulb-type blower sold specifically for this purpose.

    There are also several products on the market that will allow you to dry brush your camera’s sensor—these brushes are unique because they are made of fine fibers that are charged to attract the dust. If you go this route, make sure you read the instructions thoroughly and always use the product exactly as it was intended—that is, don’t do anything that the instructions don’t specifically say you ought to be doing.

    Now, you may find that just blowing air on or even brushing your sensor isn’t enough—some of those stubborn particles will stay right where they were no matter what you do. So you may want to try swabbing your sensor, but wait—this is really risky and should not be undertaken unless you know exactly what you’re doing. There are many great tutorials available online but because I don’t personally recommend trying this, I’m not going to try to outline the method here.

    Conclusion

    Dust is evil. That’s my basic conclusion, but I hope the rest of the information in this article has given you some practical ideas for defeating it. Above everything else, remember that you need to be careful. If you’re not 100 percent confident in your ability to use any of these dust removal methods, it’s best to leave the whole endeavor to the experts.

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