Sony has announced a pair of new “stacked” smartphone camera sensors in the Exmor RS IMX230 and an unnamed 16-megapixel variant. The IMX230 captures 21 megapixels at an f/2.4 aperture and uses a “stacked” design that Sony touts as retaining a small footprint and adds key functionality. The IMX230 also features an onboard image plane phase detection autofocus signal processing function that helps the sensor track and focus on moving objects much faster than previous sensors. It can also track subjects with 192 different autofocus points simultaneously. The new sensor is also capable of capturing HDR video at resolutions up to 4K with the IMX230 shipping to manufacturers in April 2015. Sony also announced a 16-megapixel variant of the IMX230 slated to ship by the end of next year with identical features to the IMX230.