Tuesday, July 20, 2010

Attack of the Dreaded Sensor Dust Bunnies!

In yesterday's post about HDR, I pointed out the presence of sensor dust in the "before" image. Sensor dust is simply minuscule particles that find their way onto your camera sensor during lens changes or even just normal daily use.  Most of today's newer camera models incorporate some sort of in-camera sensor cleaning to help combat dust, but even then you will still have to battle the dust bunnies at some point.
How do you know if your sensor is dirty? 

Well, generally sensor dust likes to make its appearance on your photos when you stop down the aperture to something like f/22.  At larger apertures such as f/5.6, odds are it won't even be visible.  If you want to know if your sensor is dirty, set your aperture to f/22 and take a picture of a solid color - like a piece of paper or bright blue sky.  If you see spots in your images as in the one at right, you've been attacked by the dreaded sensor dust bunnies.
Oh NO! My sensor's dirty! Now what?
First and foremost, don't panic. We'll get through this together.  Here are the steps I take when my camera starts producing images as the one above.
  1. If you're camera has "in-camera dust cleansing", this should be your first offensive attack on the sensor dust bunnies. My Nikon D40x is older technology so this weapon isn't in my arsenal and I resort to launching rockets immediately.
  2. Rockets? Yep, the Giottos Rocket Air Blaster.  Here's my strategy:
    1. Find yourself a clean, dust free, well lit area.
    2. Make sure you have either a full charge on your camera battery or connect to external power.
    3. Put your camera into "Mirror Lock Up" mode.  Check your manual for details.  You'll now have access to the sensor.
    4. Remove and cap your lens (don't want the bunnies attacking the glass on your lens either).
    5. Giottos AA1900 Rocket Air Blaster Large (Black)Holding the camera body with the lens mount facing down, use the Giottos Rocket Air Blaster to "sweep" air across the sensor.  DO NOT put the air nozzle inside the chamber but blast air up into the chamber in a sweeping motion. DO NOT use any sort of canned air products.  You don't want a shot of propellant on your sensor. The bunnies would love that, but the sensor...not so much.  DO NOT use that cheap little "air bulb with brush extension" you got as a freebie at the camera show.  More often than not, you'll blow more crap onto your sensor rather than off.
  3. The Rocket is effective at removing the easy stuff and sometimes that's all you'll need (FYI - You can also use the Rocket to blow dust off the exterior of your camera and lenses).  Obviously you'll want to take additional test photos to review your progress after each battle.  If your sensor is still dirty after the above, it's time to bring out the big guns - sensor swabs.
  4. Before we go any further it's "gut check" time. If you're the type who runs to the doctor when you get a sliver in your finger, you might consider taking your camera to a professional dust bunny exterminator. There's no shame in having someone else pamper your baby. More power to you for knowing where to draw the line.  The only problem is that sensor dust bunnies are relentless and they will eventually come back. Every time your camera needs cleaning, you're going to be without your camera.  If you're the type who reaches for the butcher knife when you get a sliver in your finger, move on to step 5. :)
  5. If the Rocket missed some bunnies, there are a variety of additional products on the market to help you remove the remainder.  The method I've used and am familiar with are the sensor swabs (also known as "the wet method").  I won't lie to you, the first time I attempted to clean my sensor was a little intimidating, but by taking my time and carefully preparing for the attack in advance, my camera was soon free of sensor dust bunnies. To help you plan your battle attack, I've included two links below:
    1. Video - "The Wet Method of Cleaning a Digital SLR Sensor" - Rather than re-invent the wheel, I'm going to direct you to the video I watched prior to attempting my own cleaning.
    2. Supplies - http://www.micro-tools.com/ - Nope, I'm not on the payroll but do recommend Micro-Tools for your cleaning supplies.  In fact, you may have difficulty finding other online resources due to regulations as to how cleaning solutions can be shipped.  Regardless, customer service is excellent and they will be willing to help you acquire the supplies you need.
That's all for this week.  Next week we'll discuss how to fix all of those photos you took BEFORE eliminating the dust bunnies.
Until next time - keep click'n.


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