If dust collects on a digital camera's imaging sensor, every photo the camera takes will be affected. Dust entering the camera while changing the lens is one of the biggest problems with digital SLR cameras featuring interchangeable lenses.

The L1 solves this problem with its dust reduction system. A special filter called Supersonic Wave Filter is positioned in front of the imaging sensor, between the low-pass filter and shutter. Every time the camera is switched on, this filter generates supersonic vibrations at a rate of around 30,000 per second to shake off dust and other particles from the sensor. The area between the sensor and the filter is completely airtight. The dust is collected by a dust absorption section below the filter.