Now while all of this time-of-flight business sounds really cool, the Kinect 2.0 is even cooler because the sensor also has built-in ambient light rejection where each pixel individually detects when that pixel is over saturated with incoming ambient light, and it then resets the pixel in the middle of an exposure. The Kinect 1.0 sensor has no means of rejecting ambient light, and as such, cannot be used in environments prone to near-infrared light sources i.e. sunlight. In fact, the Kinect 2.0 sensor’s light rejection is one of the reasons why its original developers considered using the system in automotive applications for things like a rear-view camera.
via Gamasutra: Daniel Lau’s Blog – The Science Behind Kinects or Kinect 1.0 versus 2.0.