How much time compression does the Camera app's time lapse mode apply? When I take a time lapse using the built in camera on my iPhone how much faster does the video play back relative to a normal video?
According to this blogpost from 2014, when the feature was released with iOS 8, the speed adjusts based on the length of the recording:

&lt;10 minutes -- 2 frames every second -- 15x

10 minutes to 20 minutes -- 1 frame every second -- 30x

20 minutes to 40 minutes -- 1 frame every 2 seconds -- 60x

40 minutes to 1 hour 20 minutes -- 1 frame every 4 seconds -- 120x

1 hour 20 minutes to 2 hours 40 minutes -- 1 frame every 8 seconds -- 240x

Every time the recording length doubles, the frame capture time and playback speed doubles as well. The author tested up to 8 hours and mentions that Apple referred to a 30 hour time-lapse...