charges. However, it still attracts microscopic-sized dust to the image sensor with infinitesimal force. While earthing (grounding) the camera can help reduce the problem of electrostatic dust it does not reduce intermolecular attraction. If, for example, flour were drizzled into the camera, it would still adhere to the surface of earthed metal. This kind of dust is attracted by intermolecular force. 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. History of dust reduction systems Olympus was the first to include a dust reduction system on a DSLR, featuring their "Supersonic Wave Filter" (SSWF) dust reduction technology on the Olympus E-1 in 2003. All Olympus DSLRs with removable lenses have included this system, as have Panasonic's and Leica's DSLRs; both companies use Olympus technology. Olympus Corporation was awarded an innovation prize by the Japan Institute of Invention and Innovation (JIII) in 2010 for its invention of automatic dust reduction for digital cameras. Before that Sigma was sealing the mirror box of their cameras with a protective filter behind the lens mount, preventing dust from entering the camera body. Other manufacturers, namely Sony (2006), Canon (2006), Pentax (2006), and Nikon (2007), followed suit with their own dust removal technologies. Each manufacturer uses a somewhat different system. There have been several attempts by camera magazines to test the various dust reduction systems to see how effective they are. Pixinfo, Chasseur d’Images, and Camera Labs have all published their opinions, which can be summarized as saying that none of the systems are completely effective, but that the Olympus SSWF system is significantly better than most of the others, with the Nikon system perhaps a close second. See also Ultrasonic cleaning Resonance Low-pass filter References External links Sensor dust: Cause prevention is better than cure Review of the SSWF in the E-410 at cameralabs.com Overview of the E-510 at dpreview.com, including comments on this system Photography equipment Dust