The D4s is designed to focus faster and more reliably than ever before
The D4s uses the same triedand-tested Multi-CAM 3500 FX AF sensor found in the D4 (and D800), but Nikon has improved the autofocus algorithms in the D4s to make it lock focus faster and maintain focus more reliably with fast and erratic subjects. There’s also a brand-new Group AF mode. Here, the camera uses four additional AF points above, below and to either side of the AF point you’ve chosen. This group of five AF points tracks moving subjects with increased stability and accuracy, with less risk of the focus shifting to the background. This is vital for professional sports photographers.