
The Pro mode that's already present in the camera app allows users to customize the ISO value but at the moment 100 is the lowest ISO setting, we reported that the Android 5.1 update will add an even lower value of ISO 50 which is the lowest you can find on many digital cameras. We also said that manual control of shutter speed might also be added in this update and all of that has turned out to be true.
To access all of these advanced camera features on the Galaxy S6 and S6 edge, just install a third-party camera application from the Google Play Store that has full support for Lollipop's Camera2 API. It's unclear when Samsung is going to enable all of these features in the stock camera app but for now third-party apps are the way to go if you want lower ISO values, RAW support and control over the shutter speed.