Panasonic has announced firmware v2.2 for the GH4 to make it easier to use anamorphic lenses with the camera. The new anamorphic mode allows the camera to capture video from a 4:3 aspect ratio chunk from the middle of the sensor to match the projection of specialist lenses, allowing genuine anamorphic capture, rather than digital simulation of the look.
Articles: Digital Photography Review (dpreview.com)