This morning Sigma announced the MC-31 Mount Converter to enable the use of PL-Mount lenses, commonly used in cinematography, to L-mount cameras such as the popular Sigma FP. It will cost roughly $679 (at B&H Photo), and will begin shipping in one week, on February 27th.
With a tripod mount and an all-metal body (aluminum body and brass mount and locking ring), the converter is designed to be sturdy and safe for use with expensive PL lenses. The MC-31 also has shim adjustments at two points to get the perfect fit and focus, and the lens markings are made with luminous paint to make them easier to see when shooting in low light.