Optical image stabilisation (OIS)
Optical image stabilisation (OIS) is a camera feature that moves the lens to counter small hand movements, giving sharper photos. Apple says strong magnets or metal near the iPhone's rear camera can interfere with it.
OIS relies on sensors that track the lens position, and those sensors respond to magnetic fields. Apple's advice is to avoid accessories that put magnets or magnetic metal near the rear camera. In practice, that means placing any metal ring in the centre of the phone, away from the lenses.
Apple Support: Magnetic accessories and iPhone cameras
Related terms