Dust reduction system

Every time lenses are changed, dust may enter the camera body and settle on the image sensor.

Even the tiniest (micrometre-size) dust particles or other contaminants that settle on the face of the image sensor (individual pixels of which have dimensions on the order of ~5 micrometres) may cast shadows and thus become visible in the final image as more or less diffuse grey blobs, depending on aperture.

Whenever the camera is turned on, a piezoelectric driver induces a vibration in the filter glass, shaking dust off.

Olympus invented the system, called a Supersonic Wave Filter (SSWF), and licensed it to Leica and Panasonic.

[3] The SSWF has been included in all Olympus, Panasonic, and Leica Four Thirds DSLRs, and is often cited as a key advantage of the system by reviewers and users.

Sony and Pentax incorporate sensor shifting in their cameras with dust reduction systems.

Most of the contamination to be found on the image sensor surface is caused by dust particles as small as just one micrometre (0.001 mm) adhering to it through electrical charges.

Liquid also adheres to the image sensor by intermolecular force and such molecules adhere strongly due to their ability to get closer to the adhesion surface, making it harder for dust reduction systems to remove these type of contaminants completely.

In such instances, wiping the optical elements in front of the image sensor with cleaning fluid may be necessary.

Other manufacturers, namely Sony (2006), Canon (2006), Pentax (2006), and Nikon (2007), followed suit with their own dust removal technologies.