Samsung Galaxy S6 And S6 Edge Got Sony IMX240 Camera Sensor
The Samsung Galaxy S6 and Galaxy S6 edge pack a Sony IMX240 sensor, the 16MP unit we've seen on the Galaxy Note 4. Samsung has improved the camera module since the phablet though, widening the aperture from f/2.2 to f/1.9. This should further help low-light photography, which already enjoys the benefits of optical image stabilization.
In the previous generation the Galaxy S4 used a 13MP Sony IMX135 sensor. The selfie camera on the Galaxy S6 reports a SLS_S5K4E6, which indicates a Samsung sensor. It's a different sensor though, a 5MP one instead of the 3.7MP sensor in the Galaxy Note 4. It's most likely the same selfie camera that goes into the Galaxy A series.