The cameras in your iPhone take great photos even in difficult conditions. If you accidentally move a camera when you take a picture, the resulting image can be blurry. To prevent this, some iPhone models have optical image stabilization (OIS).1 OIS lets you take sharp photos even if you accidentally move the camera. Additionally, some iPhone models have closed-loop autofocus (AF).2 Closed-loop AF resists the effects of gravity and vibration to preserve sharp focus in stills, videos, and panoramas.
With OIS, a gyroscope senses that the camera moved. To reduce image motion, and the resulting blur, the lens moves according to the angle of the gyroscope. With closed-loop AF, on-board accelerometers measure and compensate for gravity and vibration effects. Magnetic sensors determine the lens position so that the compensating motion can be set accurately.
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 temporarily disable the sensors. This can degrade the sensors' 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.
How to avoid magnetic interference
Third-party manufacturers make some accessories with strong magnets or magnetizable metal plates that are near the iPhone rear camera (or cameras). These magnets and plates can latch folio covers, join separable cases, or attach to rigid mounts—for example, car mounts. For best camera performance, avoid accessories that use magnets or magnetic metal near the iPhone rear camera (or cameras).
If your camera still isn't working
Find out what to do if you removed your iPhone case and any other magnetic accessories and your iPhone camera still isn't working.
1. OIS is available on iPhone 6 Plus, iPhone 6s Plus, and iPhone 7 and later including iPhone SE (2nd generation). Note that the Ultra Wide camera on iPhone 11 and later doesn't have OIS, nor does the Telephoto camera on iPhone 7 Plus and iPhone 8 Plus.
2. Closed-loop AF is available on iPhone XS and later, including iPhone SE (2nd generation).