Autofocus Points Overview
Part of becoming an improved photographer is learning the ins and outs of your camera. Though it can seem overwhelming when you're a beginner - having an array of buttons, dials, and menus to familiarize yourself with - at the end of the day, understanding how all those features work will only empower you to take better photos.
One of the most helpful yet most underutilized camera features is autofocus points. In this quick guide, we offer an overview of what autofocus points are and how to use them.
Autofocus or AF points are what's used to determine the location of focus in an image. Typically, the more expensive the camera, the more autofocus points it will have. For example, an entry-level camera like the Nikon D3300 has 11 autofocus points. By contrast, the professional-grade Sony A9 has 693 autofocus points.
Autofocus Points and Automatic AF Selection
When looking through your camera's viewfinder (or, on some cameras, even when looking at the Live View screen), you'll see an array of points as shown above.
When you press the shutter button down halfway, one or more AF points will light up, typically in red, and indicate to you which points the camera is using to focus the shot.
When using automatic AF, the camera obviously chooses which points it deems to be the most appropriate. This works well in many situations, particularly if there isn't any movement in the shot and there's nothing between your lens and the subject that would disturb the focus.
For example, automatic AF selection is perfectly fine for taking a portrait like the one above.
By pressing the shutter button halfway, the camera would acquire a focal point on the subject's face, resulting in a portrait that's nice and sharp.
However, if you introduce movement into the shot, like tracking an animal as it runs, or you're shooting through something, like plants or tree branches in the foreground, automatic AF selection often does not work.
This is because the camera can easily get confused and select the wrong focus point.
For example, in the image above, note the branches in the foreground. In automatic AF selection, the camera might select the AF point that's on the foreground branches because they are nearest the camera. That would result in the tree branch being in focus and the model being out of focus.
In this scenario, using manual AF selection is the way to go. We'll discuss that in the next section.
Manual AF Selection
As the name indicates, when you use manual AF selection you determine which focus point the camera uses to focus the image. Needless to say, in some situations, this can lead to a much more precisely focused shot.
The method for determining which AF point is used for focusing varies from one camera to the next.
For example, on some cameras, you have to navigate through a menu system to select the desired AF point. On others, you can use hot buttons on the back of the camera body for a more direct method of accessing the AF points.
Some cameras with touchscreen capabilities even allow you to select the AF point by simply touching it on the LCD.
If you aren't familiar with how to manually select the AF point, refer to your camera's owner's manual for instruction.
Also check out the video above by Mark Wallace in which he explains autofocus points and demonstrates the value of choosing which AF point is active.
Though Mark uses a Canon camera for his demonstration, you can still see how choosing the AF point yourself can have a dramatic impact on the image.
Another factor that influences whether your images are sharply in focus is the focus mode you use - single shot, continuous, manual focus, and so on.
For a detailed overview of focus modes, check out the link in the Learn More section below.
When the Number of AF Points Matters
As I noted earlier, entry-level cameras tend to have fewer AF points than top-of-the-line models.
As I also noted earlier, if you're photographing stationary objects and there isn't anything between your lens and the subject, your camera will do a good job of focusing. That means that in those situations, the number of AF points isn't as important.
However, there are times when having a wide array of AF points is advantageous.
When shooting actions shots - your kids playing sports, your dog running in the backyard, and the like - the more AF points you have to work with, the more likely your subject will be in focus.
This is true whether you use automatic AF selection or if you choose to manually select AF points.
That's because with a higher number of AF points, there are many more choices and a greater chance that the subject will be near an AF point for either your camera or you to select.
So, if you typically shoot portraits or landscapes, the number of AF points won't be as impactful to your work as it will if you prefer to shoot action shots.
If you're looking for a new camera, just bear that in mind as you make your choice!