The D700 has distinct modes for how and when to focus. We’ll examine each of those modes as a starting point in our understanding of autofocus with the Multi-CAM 3500FX AF Module. We’ll tie together information about the Focus modes, AF-area modes, and Release modes since they work together to acquire and maintain good focus on your subject.
In fact, this chapter encompasses information found in the User’s Manual chapters on Focus and Release modes (User’s Manual pages 71 to 104). It goes deeper than merely looking at the AF Module alone, since other related camera functions—such as the Release modes—directly affect how the AF system performs.
In Figure 3-2 are four pictures of the controls we’ll use in combination to change how the camera focuses and captures images.
Notice in the last picture in Figure 3-2 how the Multi Selector has a locking ring around it. At the top left of the ring you’ll see a dot and an L. Move the switch to the dot setting, which unlocks the internal AF “sensor point in use”. Otherwise, you won’t be able to move the AF sensor point around the viewfinder within the 51 available points.
If you want to use the D700 as a point-and-shoot camera, ensure the AF sensor rectangle is centered in the viewfinder, set the lock on L, and the center AF focus is all the camera will use in Single-point AF mode. I leave mine unlocked all the time but then I check as I’m focusing to make sure I am using the AF sensor I want to use. I can move a single AF sensor, or a group of sensors, around the array of 51 available sensors with the Multi Selector.
Be aware that 15 of the 51 AF sensors on the D700 are cross-type sensors, which means that they will initiate focus in either a horizontal or a vertical direction. The center three columns by five rows of AF sensors are cross-type. All sensors outside of the three center columns of sensors are only sensitive in a horizontal direction. Figure 3-3 has the sensors that are cross-type colored red.
