Road to Sharp Images - Understanding Focus Area Modes & Focus Points

Every DSLR camera is equipped with focus points. Focus points help the camera detect contrast, which (to make a long story short), help the camera focus on a scene more accurately. Some of these are regular vertical AF sensor points and some come with a newer cross-type technology. The cross-type sensors detect contrast vertically and horizontally, which means that the more cross-type AF sensors your camera has, the more efficient your Autofocus will be. It's also helpful to know that the more AF points your camera has, the better focusing results you'll get with moving subjects. 

AF-Area Modes

On my Nikon D7000, I change this setting by pressing this button and scrolling my front wheel dial. 

Understanding Focus Area Modes - www.mommatography.com

On an entry-level Canon DSLR, you might change this setting by pressing this button and then selecting your Focus Area Mode. If you're unsure about your camera, check your camera's manual. 

Understanding Focus Area Modes - www.mommatography.com

Single-Point AF-Area 

Known as Single Point (Nikon) or Manual AF Point (Canon), this mode uses one focus point (one specific area) that you choose to focus on your subject. This mode is great for precision. It's as simple as that. Here's what it looks like when you do Manual point selection on a Canon screen; only one focus point is activated.

Understanding Focus Area Modes - www.mommatography.com

Dynamic AF-Area 

Known as Dynamic (Nikon) or AF Point Expansion (Canon) mode, you first choose the single focus point; once focus is achieved on that area, you can pan (or follow) your subject, trying to keep it close to the focus point. Your camera will then try and help you track the focus, by using the surrounding points. This mode works really well for moving subjects. You can also choose how many focus points you want to use; every camera is different and has a different number of these points. If you want to track a small area of the scene, you can choose a smaller number of focus points. If you want to track a subject using the whole viewfinder, you should pick the highest number of tracking points. See my example below.  

Understanding Focus Area Modes - www.mommatography.com

3D-Tracking Mode

Some DSLRs have a 3D-Tracking Mode, where you pick the focus point and your camera will automatically activate as many focus points as needed to have an efficient way of tracking your moving subject. It uses a color-recognition technology so you can recompose, while it tracks, for instance, a red car driving down the street or a white bird flying around birds that might be black. The difference between 3D and Dynamic Mode is that you choose the area you want to focus in Dynamic Mode. 

Here's an example of what the different Focus Modes look like on a Nikon (image source from Nikon).

Understanding Focusing Area Modes - www.mommatography.com

It can be a little confusing to remember how our Focus Modes and Focus Area Modes work. Hopefully these posts help you understand how your Autofocus system works a little better. Try some of these different settings and see which Focus Area Modes work best for you, your subject matter and your camera!