Look at the enlarged section of the photo of Snow Geese that I took at Reifel Refuge in BC yesterday. All those black specks in the sky are not drifting cottonwood fluff, or precipitation, or out of focus lead shot. They’re the dust bunnies living on my sensor.
Here is yet another problem we didn’t use to have. Oh yes, before an important job I’d open the shutter and make sure there weren’t any stray hairs on the edge of the film aperture. But film is transported through the camera, and it is exposed to the air for a tiny fraction of a second. Now, though, the film doesn’t move. It lives motionless at the back of the camera, with a dust-attracting electronic charge no less, open to the world.
I have scoured the Internet looking for the state of the art. Well, as with all things digital, there are competing states-of-the-art that volley for the right to be the One True Accurate Way. I first bought the blue speck-grabber Pro Kit (Kinetronics), with an alarming instruction sheet on how to approach and touch your sensor, how to clean the wands, and scary denials of responsibility for damage. This technique requires that you actually see and identify an offending mote, then swoop in and remove it. I look at my sensor, under a bright light, with the magnifier hood I wear to spot prints, and I see nothing. The blank skies in my digital files say otherwise.
Then I bought the Sensor Swabs using Pec-Pads and a methonol solution from Fargo Enterprises. Their website has extensive instructions on making your own paddles, and instructions on how to fold a non-abrasive pad onto it, and how to dip and swab your sensor just so. They also sell a package with all the pieces put together, which I bought. I wet the pad, made a swipe in each direction, then looked at a file. It mostly moved the pieces around, and added a few big chunks of crud as well (probably dislodged from elsewhere in the camera body).
The instructions from Canon are to hold your camera upside down (so the dust falls out), and use a hand blower on a regular basis. This I do nearly everytime before I take my camera out. I also take care to turn the camera off before changing the lens, as the sensor powered up is an electronically charged dust magnet. As far as Canon is concerned, if you touch your sensor with any of the above products, your warranty is kaput.
I finally concluded that I needed a professional cleaning. Phototronics, in the Seattle Photo District, charges over $90 for a cleaning. That wasn’t going to fit into a regular maintenance program for me. Cameratechs in Ballard has a special for March, for ASMP members only: free sensor cleaning. They plan to offer this every year. For civilians, and for the rest of the year, it’s $39. This I can do on a regular basis.
Bill Jones at Cameratechs says the only way he’s found to truly clean a sensor is by close visual examination under a stereo microscope. He uses a non-abrasive wipe, of course, with a mixture of isopropol alcohol and Windex ("It’s what Canon uses," he reassures me.) He says it takes about a half an hour to really get a sensor clean.
It looks like I’m going to be making the trip to Ballard every few weeks now for the rest of my digital career.