Keeping Your DSLR Sensor Clean

I'd like to tell you what I have learned so far about dust and DSLRs.

Dust specs show up in digital photos usually in skies, when photos are shot with narrow apertures such as F11 or narrower. Usually small dust doesn't show up when shooting at wide apertures. In most cases dust specs can be easily cloned out in Photoshop. However, it's important to prevent dust entering your camera.

Professionals prefer to change lenses in dust free environments, and they make the change so that the hole in camera body is pointing downwards. Dust particles follow gravity and they move more likely down than up.

If you remove lens, immediately place body cap on your camera. Make sure also to keep rear cap attached when storing the lens.

It is best to change lenses in a place with as little ventilation as possible. Moving air moves dust particles, so windy weather is hardly ideal. Get inside car or shelter yourself from the wind before making the change.

If dust doesn't show on your photos, you're probably fine. If you constantly shoot landscapes with narrow apertures and notice dust specs on skies, it might be a problem that requires action.

Although most modern DLSR's have some kind of active dust reduction mechanism, it doesn't remove all dust. Big bulb blower without the brush tip is a tool of my choice. Choose one from the expensive side rather than the cheapest.

Set the camera into manual cleaning mode, and remove the lens, and make few blows with the blower. Make sure the tip of the blower never touches the sensor. I don't recommend to insert the tip past the shutter curtains. If somehow the shutter would close while cleaning and bulb blower's tip's blocking it, you'll probably end up with damaged shutter.

You can test the result by taking picture of a blue sky, or a white wall. Use narrow aperture, for example F11, or F22. If dust specs still exist, repeat the cleaning process.

There are also tools that allow you to wipe the sensor directly. Personally I feel it's a bit too risky. If bulb blower isn't enough, I recommend to take the camera to the manufacturer's official maintenance for cleaning.

Some cameras also have automatic dust spec removal function, which registers the sensor spots in photos and automatically removes them in post processing.

When we shoot long enough with DSLRs we get used to removing occasional dust specs in post processing. In most cases it isn't big problem. What you need to take are are the big spots when they appear. In film age, dust was actually much worse problem, because it couldn't be removed as easily as nowadays.