Olympus posted that new article about the very first Olympus camera with SSWF:
What you see here is rare, actual, slow-motion footage of a prototype Supersonic Wave Filter (SSWF) dust reduction system being tested a year or so before the debut of the Olympus E-1 DSLR camera in 2003. Each OM-D is equipped with a much more advanced SSWF dust reduction system, which vibrates over 30,000 times per second to remove dust particles from the image sensor every time you turn the camera on. But realizing this system wasn’t so easy.
By applying a conductive coating to the glass protecting the sensor, Olympus engineers were able to remove dust that stuck to the sensor by static electricity. Being able to remove the dust adhered to the sensor by intermolecular forces was a much larger challenge, and for this the Supersonic Wave Filter was invented.
However, the first SSWF only generated around 100g of acceleration, and the dust didn’t even budge. Many rounds of trial and error were carried out, and Olympus engineers utilized resonance to amplify the vibrations so that an acceleration of thousands of g was achieved. Still, not all dust fell from the sensor. Only the dust located at the vibration crests fell, and the dust located at the nodes of the vibrations stayed put. Finally, the engineers managed to generate the vibrations so they peaked uniformly across the sensor, removing all dust particles.
The SSWF dust reduction system has since been providing Olympus interchangeable lens camera users with clean, crisp images, receiving various accolades and high praise around the world.
