The latest teardown of iPhone 5S by Chipworks shows that IPhone is 5S using Sony IMX145 stacked CMOS Exmor-RS sensor, the sensor is approx 15% bigger compared to old sensor and hence the system delivers a 33% increase in light sensitivity.
From past year Nokia high-end Windows phone become the first choice of photographers due to larger sensor size and excellent low light capability, now from iPhone 5S we can clearly see Apple is also putting attention towards BIG sensors to improve image quality and attract more photographers.
src – Chipworks