You will be able to set ISO levels, exposure times, and so much more. There are several camera replacement apps in the Play Store that will give you a lot more control for capturing even cooler photos. However, the Google stock camera app leaves a lot to be desired, especially for those who like to adjust a lot of settings. The Nexus 6P has an amazing camera with fantastic low light performance.
You will need to enter your Google password one more time, for the last time. Scroll down to Fingerprint Authentication and check it.