A Swiss security researcher managed to dissect a video recorded with the kinematic mode of iPhone 13 to "release" the distances card associated with video.For those who just come out of hibernation, let us remember that the kinematic mode applies a vague effect on videos, to better highlight a subject.The iPhone 13 analyze the environment for this purpose to determine the distance between objects and apply the vague effect in the right place.

This treatment is carried out in real time, but it can be changed after filming.This is why the file saved by the iPhone 13 does not only contain a video track and an audio track, it also incorporates an additional track for this distances card.It is a proprietary and not documented format, but this researcher has managed to understand its functioning and especially to extract it.What view the work base of the kinematic mode in parallel with a video:

Several lessons can be learned thanks to this extraction.The first is that the kinematic mode generates a much lower definition card: while the video is turned in 1080p, an image of 1,920 pixels wide on 1,080 pixels high, the video track of the Distance is content to320 pixels out of 180.This explains why the cuts around a net subject can be so drooling, it is because the distance measurements are still unclear.

Another essential teaching, the analysis only works on a very short distance.You can see it on the previous video: all that is close to the iPhone is in white, everything that is remote in gray.Note how the distance track is almost uniformly gray on this video shot in the street.The kinematic mode is optimized for a close subject and it works badly in any other context.

On the iPhone 13 Pro, Apple could have obtained much better results by exploiting the Lidar, this laser dedicated to the measurement of distances precisely.This same researcher proves it with this other video which juxtaposes three elements: a video in kinematic mode, the distance card generated by the mode and finally a map of the distances produced by the Lidar.We can clearly see that the latter is not only more precise (the limits of objects are sharper), it is also more complete and detects distances later.

Why not have used the Lidar in this case?Perhaps because the iPhone 13 are devoid of it and Apple did not want to differentiate the function on both ranges.Maybe also because the Apple A15 is not yet enough to manage the lidar more precise distance card.

Anyway, this is information to keep in mind to better use this novelty of the iPhone 13.Choose your staging carefully to get better results and in particular, consider getting closer to the main subject.