Modern phone camera generally set their time from GPS or the cellular network, and so the timestamps on those images are usually accurate to within a second.
Other cameras (not on phones) are increasing using this. However many cameras still don’t have GPS, and there are lots of older cameras out there.
This issue cam up in the Twentynine Palms UFO case, where the times on photos of the flares shot with a Sony Alpha 9 DSLR were about 15 minutes slow. I was able to find the time correction using planes in the images and ADS-B data ... Read even more
