Canon’s 5D Mark IV has built-in Wi-Fi and shoots 4K video

The Dual Pixel sensor’s pixels have a dual photodiode construction. This sensor design means the sensor can receive an A and B signals from the subject and to detect any phase differences between the two signals, allowing them to attain focus as part of the Dual Pixel AF system. When capturing the image, the sensor obtains the picture info from the combined A and B image signals. This technology making both focusing and image shooting possible with the same sensor.

During Dual Pixel RAW shooting, a single RAW file saves two images into the file. One image consists of the A+B combined image data and the other only the A image data. This means the Dual Pixel RAW files contains both the normal image and also any parallax information, which can be measured and subject distance information extrapolated. As Dual Pixel RAW images contain two images they are therefore double the file size of normal RAW images.

http://www.canon.co.uk/cameras/eos-5d-mark-iv/dual-pixel-raw...