✔Canon EOS 70D + Canon EF-S 18-55mm f/3.5-5.6 IS STM
✔Nikon D7100 + 18-105mm f/3.5-5.6G ED VR DX
With AF tracking, once you choose the subject and press the shutter release part way down, as the subject moves, the autofocus will follow it. No more out of focus shots.