Why does the slow motion photography of the iPhone 6 camera flicker?

That’s because you turned on fluorescent lights. Fluorescent lights are inherently stroboscopic, but the frequency of flashing is too high to be detected by the human eye.

When you shoot a video in slow motion mode, the shooting speed is 240 frames per second. For example, one second of action is broken down into 240 photos, and it is difficult for the human eye to detect it if it is basically above 24. (For example, the frame rate of movies and games is high because of different principles. Please search it yourself.) This virtually increases the human eye's perception of flicker by ten times. In fact, it is improved by the mobile phone, so it is displayed on the screen. Flash as soon as it comes out