Any DSLR or mirrorless camera that takes interchangeable lenses can collect dust or other debris on the sensor surface. Sensor dust can be annoying at best, because it produces dark diffuse spots in your images that become more even more obvious if you use heavy contrast and sharpening adjustments.
The risk of getting dust on the sensor increases considerably if you change lenses in dusty conditions.
It is possible to remove dust spots in software using spot removal tools, but this can be time-consuming. Nikon has a ‘Dust Off’ system that uses a dust ‘reference’ image to identify the location of dust spots and then removes them, but you have to be using Nikon’s own software. Software tools will solve the problem, but it’s better not to have a dirty sensor in the first place.
Sensor cleaning can be done automatically by the camera or manually by hand. In-camera sensor cleaning uses high-frequency vibrations in an attempt to shake any dust particles free of the sensor. Many sensors also have anti-static coatings designed to repel dust particles.
In-camera sensor cleaning is only partly successful. It doesn’t work with ‘sticky’ particles such as fibres or pollen or other organic material. This is where you need to use manual sensor cleaning.
With mirrorless cameras this is easy because the sensor is exposed and near the front of the camera. With DSLRs you need to use a special sensor cleaning mirror up mode and reach further into the body.
If you’re lucky, a ‘dry’ clean will work. This could mean using a blower (a ‘Hurricane’ blower), for example, to blow dust and debris from the sensor surface with the camera held facing downwards so that dust falls away through gravity. You can also get anti-static brushes such as the Arctic Butterfly, or sticky dust removing pads (Dust-Aid). Any cleaning system that involves direct contact with the sensor, however, risks adding more debris than you actually remove.
For more stubborn dirt or debris, you’ll need to resort to ‘wet cleaning’ using specially designed sensor swabs and sensor cleaning fluid. Here, it’s essential to use a fresh, clean swab each time, and to avoid dragging dust and debris from edges of the sensor and its mount and on to the sensor surface.
Sensor cleaning is a delicate, skilled task, which is why many photographers choose to get it done at dedicated service centers instead.