The GF6 boasts high-speed, high precision Light Speed AF (auto focus) including practical full-time AF and tracking AF is available for video recording.

ENGADGET: Panasonic Lumix GF6 announced for the US, shipping in June for $600

Users can opt to focus manually or can take advantage of the full-time AF while recording to help ensure faces are in focus or track a moving subject.

ENGADGET: Nikon unveils lightweight, full-frame D600 DSLR -- hands-on and low-light samples (video)

The GF6 records 1920 x 1080 at 60i (60 Hz) full HD video with full-time AF and high quality stereo sound in the AVCHD format which excels in both compression efficiency and compatibility with AV equipment for playback.

ENGADGET: Panasonic Lumix GF6 announced for the US, shipping in June for $600

While Nikon pioneered HD video in a D-SLR, Nikon is now introducing another industry first to enrich the user experience: The D3100 is the first D-SLR to implement full time AF for D-Movie video shooting and while in Live View mode.

ENGADGET: Nikon D3100 gets real, adds 1080p movie mode with continuous autofocus

The camera's subject tracking of moving objects in three dimensions, with full time servo AF (AF-F), ensures focus of moving objects throughout filming.

ENGADGET: Nikon reveals D5200 SLR with D7000-taunting specs: 24MP sensor, 39-point AF, wireless port (hands-on)