 Unlike most consumer cameras, which use color sensors based on a Bayer color array, the SD14 uses a Foveon X3 sensor.Another unusual feature is the fact that the infrared filter is fitted to the lens mount rather than the sensor and doubles as a dust protector, sealing the mirror and sensor compartment, and can be removed easily, to allow infrared photography.The camera uses the SA mount, for which only Sigma itself manufactures lenses.