The 1.4x HD PENTAX-DA AF Rear Converter AW from Ricoh is compatible with Pentax KAF2 mount lenses on select DSLR cameras. It mounts between the camera body and lens, and increases the focal length of the lens by 1.4x, while reducing the aperture by 1 f/stop. The minimum focus distance of the lens is preserved, as are auto focus and auto aperture functionality. The rear converter works flawlessly with both the camera-driven AF system and the lens-driven AF system, including that of the SDM and DC-series lenses. The camera's firmware must be updated to the latest version before using the autofocus function.