Understanding Single and Dynamic Autofocus Settings in the Nikon D200

The Nikon D200 has an array of four different autofocus methods, and some differences in how they work between AF-S and AF-C modes.

In figure 3 we see an image of the AF Area Mode Selector switch on the back of the Nikon D200. We’ll discuss each of the four settings in enough detail that you’ll feel more comfortable using the modes fitting your style of photography.

Spend a little time testing each of these AF modes, and in no time, you’ll feel comfortable with each of them. Then, at a moment’s notice, you‘ll know just which mode will best serve your purpose.

Single Area Autofocus

Most photographers are perfectly happy to use the simplest autofocus setting, “Single Area AF.” With this setting your camera locks on to slow moving and static subjects using a single focus area of the eleven available in the Nikon D200. Most others would use the center AF sensor, or toggle to other sensors, with the multi-selector thumb switch. Others lock focus and then move the camera to the final composition before taking the picture. In figure 5 there’s a simplified example of a D200 focus screen with Single Area AF enabled, and the center AF sensor selected. The plus sign shows which sensor is in use, and the red bracket shows which sensor you have selected. Sometimes these are not the same (as we’ll soon see).

(Please Note: You will never actually see a “+” sign in your camera’s viewfinder. I, and Nikon’s manual writers, use the “+” sign to symbolize which sensor is actively seeking or focused on a subject, which could be a different sensor than the one you have selected and that lights up in red.)

The multi-selector thumb toggle switch allows you to select any of the 11 sensors seen in figure 5. This mode works best for relatively static subjects, like nature, family snapshots, and slow moving wildlife. The sensor in use will briefly light up in red when first selected.

Single Area AF is great for the majority of photographers, and is quite easy to understand and use.

Dynamic Area Autofocus

This “Dynamic” AF setting allows you to control the sensor focal point, like in Single Area AF, but gives you a margin of safety in case your subject moves out of range of the selected sensor. All the AF sensors are active, so the subject will be tracked by the other sensors as it moves across their areas. In figure 7 is the simplified D200 screen to show how extensive the area of focus actually is. Notice that all the 11 AF sensors are active and seeking a subject (see + signs). But, also notice how the center sensor is selected as symbolized by the red bracket in the middle. You can move the primary focus area around at will, like in Single Area AF, but remember that all the sensors are active in case of quick movements.

It is important that you leave custom setting a5 turned on with this mode; otherwise, any intruding subjects might get the camera’s attention. Remember, setting a5 controls Focus Tracking with Lock-On. If you were focused on a rabbit hopping along the ground, and a bright red bird landed behind him, the D200 might just decide it likes the bird better and switch focus. Lock-On (a5) prevents that from happening by forcing the D200 to track the subject you first focused on.

Since Dynamic Area AF is truly dynamic, it sees any high-contrast subject in any of the 11 focus areas as fair game for autofocusing upon, even though you have a different sensor selected with the thumb switch. It doesn’t matter if the new subject is in front of or behind the old subject. If it has more contrast, or is larger and brighter, the Nikon D200 will eagerly seek to change to that new subject. By leaving custom setting a5 set to ON, the Nikon D200 is much smarter and tracks your real subject until it leaves the frame, or you take the picture.