Larryshuman wrote:
Nikon has several sensors that they call dynamic- 3D, D25, D9, auto & D51 (D3) , Grp4 (810). Then there is the good ole single sensor. These are obtained by pressing the center button on the AF switch (left side lens flange bottom)While pressing turn the top wheel and you'll page thru all of them.
Nikon has several modes that use different numbers and patterns of sensors. With those modes except for single spot. Generally in any multi sensor mode whatever is closest to the photographer and falls within the pattern will be the sharpest focus. With single spot you can put it on the eye and focus. What eye detection gives you is faster acquisition since you don’t have to physically move the focus point and the ability to track the eye. The caveat is that Nikon has both human eye detection and animal eye detection, but animal eye detection is specifically designed for dogs and cats so it may or may not work with birds.