Shooting with a digital SLR camera provides a lot of benefits over non SLR models, but the increased functionality comes at a price – sensor dust. Since an SLR camera is an open system (one that allows users to change lenses) the probability of dust entering the camera is nearly unavoidable. Learning to deal with dust is a part of owning a digital SLR.
After I made the move from film to digital, the discovery of dust on my camera’s sensor was a major shock. But now after a couple years of shooting digital and dozens of sensor cleans, I now look at it as just a minor annoyance.
There are two types of digital SLR shooters – those that have dust on their sensor and those that will have dust on their sensor. I believe that every photographer should learn how to handle it. Here are the steps I take with my cameras.
To see if you have dust, stop your camera down to its smallest aperture (usually f/22-32) and take a shot against a blank scene (blue sky works well). The dust will show up as dark blotches. The photo above shows numerous dust spots that I recently had on my Canon 5D. Keep in mind that these spots will only show up on photos taken with smaller apertures and they can easily be removed in post-processing, so you don’t have to obsess over cleaning them daily.
The first step I take in cleaning is to set my camera into “SENSOR CLEANING” mode. This is a menu function that opens the shutter and locks the mirror up allowing access to the sensor. Since moving these out of the way uses power, be sure to have a sufficiently charged battery before starting.
Once I have the camera in cleaning mode, I remove the lens and blow off the sensor with the bulb blower. I do this with the lens opening aiming down to allow the dust to exit. Take care to not touch anything inside the camera with the tip of the blower. If I only have a few dust spots, this will frequently be the only step necessary since the blowing air will dislodge the dust.
To remove stubborn dust spots, I use the sensor cleaning solution with a swab. This is the most effective method for me. I put a few drops of solution on the swab and make two passes across the sensor – once in each direction. I use very little pressure on the swab. It is very imperative to only use a swab once on each side to avoid re-contaminating the sensor with previously removed dust.
Note that most camera manufacturers state in their user manual that you are to never touch the sensor with anything and using this method can risk voiding your warranty. However, if you took your camera in to be professionally cleaned this is probably the method they will use.
Sensor dust is part of the price we pay for shooting with the great digital SLRs that are available today. The internet is full of stories of photographers obsessing about every little speck of dust. Don’t be like these shooters and let it consume you. Learn how to clean your own sensor when needed and spend your time worrying about the next great photo instead of a microscopic piece of dirt.