Start with the subject, not the menu
Autofocus is the camera’s way of adjusting the lens to make a chosen part of the scene look sharp. The first decision is usually whether the subject will stay at roughly the same distance or move toward or away from the camera. Single autofocus is suited to the first situation; continuous autofocus is designed for the second. Face detection answers a different question: which part of the frame should the camera try to focus on?
Camera menus use different labels. Single autofocus may appear as AF-S or One Shot, while continuous autofocus may be called AF-C or AI Servo. Face or eye detection may be listed under subject detection, tracking or autofocus-area settings. These names are useful clues, but your camera’s manual is the best guide to what a particular setting does.
Single autofocus: lock focus for a still subject
In single autofocus, the camera focuses when you half-press the shutter button, then generally holds that focus distance while you keep it half-pressed. It is a straightforward choice for a stationary object, a posed portrait or a landscape detail. Select a focus point or area over the part you want sharp, let the camera confirm focus, and take the picture.
Holding focus can also help you recompose: focus on your subject, keep the button half-pressed, then adjust the framing before shooting. Be careful if you move closer to or farther from the subject while doing this. At close distances or with a shallow depth of field, even a small change can leave the intended detail soft. If the subject or camera has shifted, release the button and focus again.
Single autofocus does not freeze motion. If someone steps forward after focus locks, the camera may still be focused at the old distance when you press the shutter fully. Switching modes—or waiting for a moment when the person is still—can give you a better chance of a sharp result.
Continuous autofocus: keep adjusting as distance changes
Continuous autofocus keeps checking and adjusting focus while it is active, commonly during a shutter half-press. Use it when a child walks toward you, a pet moves around a room or a cyclist changes distance from the camera. Rather than locking onto one distance, the camera tries to keep up as the scene changes.
The focus-area choice matters here. A small point can work when you can keep it on the subject; a wider area or tracking option may be easier when movement is unpredictable. Start focusing before the decisive moment and follow the subject as steadily as you can. If the camera begins focusing on the background instead, move the active area back onto your subject or pause and reacquire focus.
Continuous autofocus improves your ability to follow movement, but it cannot guarantee a sharp photo. The shutter speed also needs to be fast enough for the motion you want to stop, and the camera must be able to see the subject clearly. A motion-blurred image is not always an autofocus failure.
Face detection: tell the camera what matters
Face detection looks for a face in the frame and gives it focusing priority. Some cameras offer eye detection as a further option, aiming for an eye rather than the face more generally. This can be helpful for portraits, video calls recorded with a camera, or candid pictures where manually placing a small focus point would slow you down.
Face detection is not usually a replacement for choosing single or continuous autofocus. On many cameras, it works alongside one of those modes: the camera detects the face, then either locks focus or keeps updating it. The exact combinations vary by model. Face detection can also lose the subject when a face turns away, becomes obscured or is too small in the frame. With several people present, check which face the camera has selected; it may not be the one you intended.
A simple way to choose and troubleshoot
For a still subject, begin with single autofocus and a focus point placed on the detail that matters. For a subject changing distance, try continuous autofocus with an area you can keep on them. For a person, turn on face or eye detection if your camera offers it, then check whether single or continuous autofocus better matches their movement. You can change the combination as the scene changes.
When a photo looks soft, review where the camera focused before changing every setting at once. If the background is sharp, try a smaller focus area or confirm the selected face. If nothing is sharp, check for camera shake, subject motion or a lens that is too close to focus. Practicing with a stationary object and then a moving person will make the differences between modes easier to recognize than menu labels alone.
