Sony's Exmor RS sensor already has hardware HDR, and can take HDR videos in real time. They should ship with many of the high-end smartphones this year. http://www.dpreview.com/news/2012/08/20/Sony-Stacked-CMOS-se...
Skipping all the details, it's because you have a left eye and a right eye, not an up eye and a down eye.
Sony's Exmor RS sensor already has hardware HDR, and can take HDR videos in real time. They should ship with many of the high-end smartphones this year. http://www.dpreview.com/news/2012/08/20/Sony-Stacked-CMOS-se...
Skipping all the details, it's because you have a left eye and a right eye, not an up eye and a down eye.