Many photographers will tell you that their least favorite shooting situation involves a portrait with the sun to the subject's back: there's a good chance the shot ends up an unintentional silhouette study unless the shooter meters just perfectly from that grinning face. Apple has just been granted a patent for the metering technique that takes all the guesswork out of those human-focused shots on an iOS 5 device like the iPhone 4S or new iPad. As it's designed, the invention finds faces in the scene and adjusts the camera exposure to keep them all well-lit, even if they're fidgety enough to move at the last second. Group shots are just as much of a breeze, with the software using head proximity and other factors to pick either a main face as the metering target (such as a person standing in front of a crowd) or an average if there's enough people posing for a close-up. You can explore the full details at the source. Camera-toting rivals, however, will have to explore alternative ideas.