According to a recent patent application, Canon could be working on a development of its Dual Pixel AF system. Launched in 2013 in the EOS 70D, DPAF improves autofocus speed when using contrast-detect AF. Around 80% of the pixels on the image sensor incorporate two separate light-sensitive photodiodes. The signal from these is combined when capturing an image, but can be split during autofocussing, so the camera can measure the difference between the two individual signals to determine the distance of your subject more quickly. It's proven to be an effective way to speed up contrast-detect AF, as without DPAF such focussing can be prone to focus hunting.
