A general rule of cleaning DSLR sensor by yourself is, not to do it! If you insist however, here are the steps to follow to increase your chance of success.
- Have the sensor swab ready. They often come with different sizes that fit different camera sensors.
- Clean the lens (front and back) and mirror first using Air Blower and LensPEN.
- Set the lens to Manual Focus (MF) mode, set Aperture to 16 and ISO to 100. Take a picture of a sheet of white paper. Double check if sensor cleaning is required.
- Remove the lens from the camera. Use the configuration menu to set the camera to Sensor Cleaning mode – now the mirror should lift up.
- A couple of sharp blasts from the air blower to dislodge the dust.
- Apply no more than 3 drops of cleaning fluid to the swap. This is very important – the residual of water is much worse than the dust.
- Don’t blow air to the sensor after cleaning. It only gets dust onto the sensor instead of removing them.
- Place the swab on one end of the sensor, put enough pressure to bend the swab, move one direction across the sensor and return for another across.
- Turn off the camera to close the mirror, put on the lens and shot another picture to see the result
I was frightened by what I saw after using the first swab. It’s much better after 7 or 8 tries. Finally after the 11th swab was used, I got a clean sensor.