The Nikon D3300 has 11 available autofocus points, which are indicated in the viewfinder by the markings labeled in this figure. Should you use one focus point or many? Here are some tips to help you out.
The AF-area mode tells the camera which autofocus points to consider when establishing focus. You have these choices:
Single Point: This mode is designed to quickly and easily lock focus on a still subject. You select a single focus point, and the camera bases focus on that point only. This option is best paired with the single-servo (AF-S) Focus mode, which is also geared to still subjects.
Dynamic Area: Dynamic Area autofocusing is designed for capturing moving subjects. You select an initial focus point, but if your subject moves away from that point before you snap the picture, the camera looks to surrounding points for focusing information.
To use Dynamic Area autofocusing, you must set the Focus mode to AF-C or AF-A. In fact, the Dynamic Area option doesn’t even appear when the Focus mode is set to AF-S.
3D Tracking: This one is a variation of Dynamic Area. As in that mode, you start by selecting a single focus point and then press the shutter button halfway to set focus. But the goal of the 3D Tracking mode is to maintain focus on your subject if you recompose the shot after you press the shutter button halfway to lock focus.
The problem with 3D Tracking is that the camera detects your subject by analyzing the colors of the object under the selected focus point. If not much difference exists between the subject and its background, the camera can get fooled. And if your subject moves out of the frame, you must release the shutter button and press it halfway again to reset focus.
As with Dynamic Area mode, if you want to use 3D Tracking autofocus, you must set the Focus mode to AF-C or AF-A.
Auto Area: At this setting, the camera automatically chooses which of the 11 focus points to use, usually locking on the object closest to the camera.
Although Auto Area mode requires the least input from you, it’s typically the slowest option because of the technology it uses. First, the camera analyzes all 11 focus points. Then it consults an internal database to try to match the information reported by those points to a huge collection of reference photographs.
From that analysis, it makes an educated guess about which focus points are most appropriate for your scene. Although it’s amazingly fast considering what’s happening in the camera’s brain, it’s slower than the other AF-area options.
You probably don’t want to use Auto Area mode unless you’re handing the camera over to someone who’s inexperienced and who wouldn’t know how to use the other two modes. Otherwise, stick with Single Point for still subjects and with Dynamic Area for moving subjects.
The Miniature Effects exposure mode always uses Single-Point mode. For all other modes that permit viewfinder autofocusing — that is, all modes except Night Vision and Easy Panorama Effects mode — you can select from the full complement of AF-area mode settings.
Here’s how to dial in the setting you want to use and specify a focus point:
Selecting the AF-area mode setting: You have two options:
Control strip: Press the i button to get the job done via the control strip, as shown here.
Shooting menu: You also can access this setting from the Shooting menu, as illustrated in this next figure.
After selecting the option from the menu, press OK to display the screen shown on the left in the figure. Then choose Viewfinder and press the Multi Selector right to access the screen shown on the right. Highlight your choice and press OK.
Either way, when you return to the Information display, notice the graphic labeled Autofocus points symbol in the figure. This symbol gives you information about which focus points are active.
A solid square indicates the selected focus point. A fuzzy square indicates that the point is active, meaning that if the camera can’t establish focus based on the selected point, it may consider the other active points. Any other points are inactive. In the figure, the symbol reflects the Dynamic Area setting, with the center point selected, for example.
This symbol gives you more information about which autofocus points are active in the current AF-area mode.
Selecting a single focus point: To choose a focus point in the Single Area, Dynamic Area, or 3D Tracking modes, look through the viewfinder and press the shutter button halfway and release it. When you press the button, the selected focus point turns red.
For example, in this next figure, the point directly over the top of the clock tower is selected. Use the Multi Selector to cycle through the available focus points until the one you want to use turns red. (It turns black again after a second or two.)
You can quickly select the center focus point by pressing OK.
Here are a couple of additional tips:
When you use spot metering, the camera bases exposure on the selected focus point. The point you choose affects the way the camera calculates flash exposure as well.
In any exposure mode except P, S, A, or M, the camera resets the AF-area mode to the default setting if you change exposure mode. So check this setting before every shoot if you aren’t using the P, S, A, or M modes.