Attack of the Visible Dust

When I first got a digital SLR camera, it somehow prompted stern words of caution about the horrors of dust from a number of acquaintances. One friend took me aside, pointed at the button that releases the lens from the camera, and solemnly proclaimed, "once you press that button, it's all over, you have to worry about dust".

Quick aside for those who haven't spent much time listening to photographers go poetic about their gear... A digital SLR (dSLR) uses a fixed sensor to record images, and the design allows the user to change the lens among a wide range of wallet-busting choices. However, since the lens can be removed, that also means the inside of the camera (and, thus, the sensor) can be exposed to air and whatever else may be floating in your air of choice (dust, oil, hairspray, imprecations, water vapor, etc.). Back in the ancient, ancient world of 10 years ago when people used film (yea, people used film), it really didn't matter too much if dust got into the camera. At most, there would be a little bit of dust on one frame, but then the camera would move on to the next piece of the photographic film and (assuming you weren't procuring your film supplies from some shady person in a trenchcoat on the corner) that new frame wouldn't bring any dust with it. With digital, that changed -- the sensor is the same physical bit of electronic circuitry for every single photo the camera will ever take, so any bit of dust that lands there will stay there until something else disposes of it.

Ok, that wasn't as quick an aside as I thought. But, moving on.

After clocking over 17,500 photos on my camera without any visible dust appearing on any of my photos, one will hopefully forgive me for starting to wonder what the whole dust paranoia was all about (actually, I still do, but that's besides the point). After all, that's more photos in 15 months than I'd taken in the rest of my life put together. I even remarked as much in a recent conversation.

Of course, as soon as I got home after that conversation and went out to take some photos of the new figs our tree is working on, I noticed that there was a slight dark blob on the photos that didn't exist outside my camera.

A quick, highly scientific test (also known as the point-your-camera-at-a-patch-of-sky-and-take-photo test) confirmed that, indeed, I had some of that fearful dust on my sensor. (Red circle added later, for emphasis. Though it would be kinda cool if there just happened to be a big floating red circle on the sky right where that bit of dust appears. I wonder whether this is how some UFO photos come about?)

I opened up my camera and peeked at the sensor. Sure enough, there was a bit of fuzz in the equivalent spot on the sensor, of about that shape. There's a zillion products out there (I found out) to let one clean/swipe/swab/wash/brush the sensor. There's also, unsurprisingly, a zillion bad ideas on how to clean your sensor (my favorite for actually-sounding-like-it-might-work-until-you-think-better-about-it is the scotch tape method; just like cleaning lint off your jacket, except it's your digital camera sensor that you're de-linting; having worked with semiconductor manufacturing before, take my word for it: Bad. Idea.).

Going for simple-is-better, I got myself an air blower. Going for why-not-get-the-funny-one, I got one called Rocket Air Blower. (It actually has really good reviews.) That took care of it in about 10 seconds. Repeating my test from earlier confirmed a clean sensor (for the photo-geeks out there: yes, I was using a small aperture for the tests). With a bit of luck, it will stay that way for another 17,000 photos. (Or, I'll need to clean it again after writing this post. But at least now I already have something to clean it with, and it will make for a funny story to boot.)

Blue Skies, smiling at me...