Covering nearly the entire sensor area, a powerful 4D FOCUS system incorporates 425 on-chip phase-detection points along with 425 contrast-detection areas for precise focusing in as little as 0.02 seconds. The density of focusing points from this hybrid AF system also enables High-density Tracking AF Technology, which is adept at tracking moving subjects in a variety of lighting conditions.
- Real-time Eye AF can be used to base focus on recognized human subjects' eyes for portraits and is available in both AF-S and AF-C modes and for both stills and video.
- Eye AF can be used when photographing animal subjects, too, with any focusing mode when shooting stills.
- Lock-on AF maintains focus on moving subjects throughout the use of a configurable frame that is set over the desired moving subject
- Expand Flexible Spot employs neighboring focus points to retain focus on moving subjects even if the originally selected point loses focus
- The Focus Magnifier function can be used for critical focus when homing in on minute subject details
- Rear touchscreen can be used for Touch Focus and Touch Tracking control and a Touchpad Focus Control mode lets you use the rear screen intuitively while keeping your eye to the viewfinder
- In addition to autofocus, the a6400 also features a Peaking MF function to benefit manual focus control by highlighted sharp edges of contrast for a more objective means of acquiring sharp focus