What is Apple's mobile phone time-lapse photography?

Since the iphone6, Apple has added time-lapse photography to the camera function. Time-lapse photography refers to the photography technology of recording at a lower frame rate and then playing at normal speed. Time-lapse photography can show the gradual change effect of a specific scene in a short time and bring people visual surprises. For example, changes in clouds, butterflies breaking cocoons and crowds can all show cool special effects with time-lapse photography.

It is troublesome to take time-lapse photography with a camera. Usually, the video is taken for a long time and then accelerated, or a large number of photos are taken at a specific time interval and imported into the later software.

However, the time-lapse photography function of iphone is very convenient. After the video is processed by the system, it will be stored in the iphone as a time-lapse photographic video. However, users cannot know and set the time compression ratio of the system.

Apple's official explanation for the time-lapse photography function is that "iOS 8 can complete all the work and take images at dynamically selected time intervals". After the test record of Frameographer developer Dan Provost, its compression ratio is as follows:

When using iOS 8 for time-lapse photography, two images are recorded every second in the first 10 minute, but if the recording time exceeds 10 minute, the frame rate is doubled, one image is recorded every second, and the original redundant images are deleted. Because iOS 8 will actively delete redundant images, it can be used to shoot movies for a long time.