Answer to Question #140567 in Electricity and Magnetism for Roman

Question

The Apple states in the Accessory Design Guidelines that with new iPhone 12 models can be used MagSafe magnet accessories. The magnets in those shall be N48H NdFeB with a 7 μm - 13 μm NiCuNi plating finish (or similar) and shall meet the requirements in Table 23-7 (page 90).
Also in the guidelines states that any other magnets accept MagSafe shall be used with iPhones. The question is, how magnet from other materials, like N52H NdFeB can influence on the iPhone, if it will be constantly used in the accessories to iPhone?

Answer 1

Internal magnets from other materials create magnetic fields that may affect the rear -facing camera with optical image stabilization. Though magnets are not likely to kill the smartphone, there is a possibility they will mess some pretty important aspects up.

A strong magnetic field can interfere with OIS and closed -loop AF. Lens -position sensors respond to magnetic fields. If you place a magnet near these sensors, the magnetic field will interfere with or temporary disable the sensors. This can degrade the sensor's accuracy and limit the range of movement available to the lenses. The camera will continue to take photos with other means of stabilization but without the benefit of OIS and closed -loop AF.