There's one big software update on the Sony Ericsson Xperia Arc S compared to the original Xperia Arc - an absolutely insane 16x digital zoom is now available when recording movies.
Using one or two steps of the zoom is fine, reducing picture quality only a little. But pulling in the full 16 times totally obliterates the quality, also making it impossible to keep the image even vaguely steady. It's technically impressive, but mostly useless. Like ITV1 HD.
Much more useful is the selection of focusing methods. You can leave it on auto, select multi-focus, engage face recognition or use the tap-to-focus option. The latter is a particularly fine option if you're filming moving things, reducing the amount of needless focus adjustments in your video clips.
Even with focus left on automatic, the Sony Ericsson Xperia Arc S does a nice job. It takes a second or two to refocus, which is just long enough to stop your films being filled with unnecessary focusing.
But image quality isn't amazing. The 720p clips are perfectly smooth, with VLC Player saying they all average a rock-solid 29.69 frames per second, but detail isn't quite there. Grassy areas turn a little mushy, with distant detail also lost in translation to 720p MP4 format.
Facial shots and close-ups are decent, but the Sony Ericsson Xperia Arc S could do a little more.