The autofocus system is way above average. Even in low-light, it can still detect skin tones. The only major problem would be in areas where non-white light is. It doesn’t sense skin tones as well. You should also only give a modest amount of trust to the camera when it’s set on 51PT3D Dynamic Area setting.
The standout thing among the autofocus system is the ability to sense an object when it returns to the viewing area. Basically, let’s say you are focusing on say an animal, and the animal moves out of the sensing area. Once that animal returns to the sensing area, the camera will autofocus on it.
This camera should also work quite well in fast-paced environments, including sporting events. It’s very responsive and fast. Plus, the viewfinder is quite large, making it easier to find the object on which you want to focus.
The battery life is quite good on this camera, even when you have a GPS unit hooked up to it. You should still be able to take thousands of pictures with it.
The picture quality has drastically improved over earlier models. The images are sharp and clear, even when shooting in low-light. The colors are more accurate. But, you should be aware that the saturation is higher on the D-3 than older models. So, some of your blues and warm colors may be a little off.
For long exposures, you need to make sure that the picture is in Long Exp NR. If not, you will definitely start getting colored, hot pixels in the shot.