A few days ago we were talking about the presentation of a new 8-megapixel sensor developed by Omni Vision, which in size and period of commencement of mass production could be introduced in some new products designed in Cupertino and especially the successor to the iPhone discord’s iPhone 5.
In that article mentioned it, perhaps, Apple's designers have added in each of the sensors higher performance while remaining a step (or two) behind the competition. And the reason was that the iPhone by, in addition to telephone, to hook onto the Internet. But if the networks of mobile operators are not quite offering performance does not make much sense to produce photos and video "heavy" (in terms of megabytes).