What resolution is slow motion video on iPhone?

iPhone 6 Plus camera problem

With the launch of the iPhone 5s, the main iSight camera gained slo-mo video recording functionality starting at 120 frames per second (fps). When the iPhone 6 and iPhone 6 Plus came around, slow motion recording was bumped up to 240 fps, provided the new speed was enabled in Settings. But at what resolution does the iPhone actually record slo-mo video?

Resolution depends on the slow motion mode:

- 240 fps slow motion is captured at 720p HD resolution
- 120 fps slow motion is captured at 1080p Full HD resolution

Despite the higher frame rate, 240 fps slo-mo recording actually takes up less storage space thanks to the lower 720p resolution.