What is image stabilisation?
Image stabilisation is a range of camera and lens adjustments used to reduce blurriness and camera shake. The most common form of image stabilisation on smartphones is Optical Image Stabilisation (OIS).
Whenever you shoot in low light, use a long lens, or if you simply aren’t holding a camera steady, you risk shaky, blurry images which can’t be fixed with editing. OIS physically moves the lens module or image sensor when you’re taking pictures to counteract any slight camera movement.
OIS is available in several older phones, as well as new releases, as it’s no longer a top-of-the-line feature. It’s been included as standard for several years.
The example below shows how optical image stabilisation affects an action shot. This is how a photo focused on a person might look if it was taken without OIS (on the left) and with OIS (on the right). The right-hand image is far crisper, cleaner and not blurred - the idea of movement is still present, but it's much easier to make out the finer details.