One of the main selling points for the newly announced Sony A9 is its superior autofocus. The autofocus has 693 point wide-area phase-detection points and according to Sony, it can do up to 20fps with AF/AE tracking. Sounds impressive right?
If you were wondering what’s a 20 FPS auto-focusing beast is good for, watch this movie from Gary Fong. It shows a pole vaulter going the entire distance of the course while the camera keeps tack-sharp focus. Not only that, it does so being “fully opened” with a 70-200mm f2.8 GM lens.