Focus Modes Explained
Single shot AF
The best mode for stationary subjects, the autofocus locks the focus position as soon as it senses it’s focused on the target. An LED in the viewfinder confirms focus has been found. In single shot AF, the camera won’t take a picture until it has achieved focus, unlike continuous focus, where the shutter can be released at any point.
Half-press the shutter release and the autofocus system continually adjusts to track a moving subject. Its predictive focus system continues to track the anticipated path and speed of the subject after you’ve pressed the shutter release, the mirror has flipped up and the exposure is taken, ensuring all of the images in a sequence will be sharp.
Auto select AF
Referred to as AI Focus on Canon DSLRs, Auto Select AF on Nikon DSLRs and Automatic AF on Sony cameras, this mode is ideal if you’re shooting a mix of static and moving subjects. The camera will automatically switch between single-shot and continuous AF, depending on whether it detects any movement within the scene.
Autofocus often struggles in low light, or with low-contrast subjects, and it can fail to keep up with extremely fast targets. If the subject follows a predictable path, such as bikes on a track, it’s often better to pre-focus on a spot that they’ll pass and then switch to manual focus to lock the focus distance in.