Do you think the 3D tracking 11 point autofocus of Nikon D90 successfully grab & keep grabbing a moving dog at a field? The lighting could be poor at the field, but the half of the time the field has a good natural lighting. I am also interested in the opinions from the owners of Nikon D300 whether its 51 points 3D tracking autofocus works any better for the dog, and also if the 51point 3D tracking of the D300 has significant advantage over the 11point 3D tracking of D90 for the particular application to take photos of the moving dogs. Thank you.