The new Sony A5100 uses a technology that Sony calls 4D AF – meaning a four dimension evaluation. The frame coverage, predictive AF and tracking when objects cross the AF subject are all impressive features on Sony’s new AF systems.
Check out the videos below.
[youtube https://www.youtube.com/watch?v=wy8TAGFC95o&w=700] [youtube https://www.youtube.com/watch?v=V-phxWVlk6M&w=700][via Image Sensors World]