01-25-2019 09:42 AM - edited 01-25-2019 09:43 AM
Recently took a trip.
Made a mistake and didn't start all the various cameras with the local date and time.
Used exiftool without issue on my Mac to time correct all the still image cameras and iPhone photos. Many thanks to Phil who has created a wonderful tool in exiftool.
Then, I got to GoPro. Well, it is a mixed bag. First, you have to understand what GoPro does. This was GoPro Hero Black 5. The burst images are recorded with one filename convention. The single images and movies are recorded with a different filename convention. Burst images (at least in my case) are lacking GPS timestamps, but were date and time stamped with the user input date and time. Movies had GPS time stamps that were irrespective of the user input date and time.
Using exiftool and time correcting the GoPro burst images to the local time the image was taken and then importing those photos into Mac Photos worked fine.
Using exiftool and time correcting the GoPro single images to the local time the image was taken and then importing those photos into Mac Photos worked fine.
Using exiftool and time correcting the GoPro movies to the local time the image was taken and then importing those movies into Mac Photos skewed the time by the numbers of hours the GPS timestamp was away from UTC (aka GMT). So, even though I corrected the normal Exif metadata, irrespective of the embedded GPS data, that movie was imported using the Exif corrected time, but skewed by the number of hours the GPS timestamp was from UTC. In my case that was 6 hours. So, just to be clear, my Exif manipulated time, but skewed by the GPS timezone.
I searched and searched for ways to correct this. Nothing satisfying.
This is my suspicion. The GPS timezone data is creating some confusion between GoPro and Mac Photos. I'm not totally sure where all the blame lies, but I suspect it is both places.
This worked for me...
- Fix the Exif time and date using exiftool.
- Leave the GPS timestamps alone.
- Change the time on your Mac to London time -- that is UTC-0.
- Now import your GoPro movies into Mac Photos.
- Your GoPro movies will now be imported and show time and date as local time and date of the shoot of the movie.
- Change your Mac time back to your local timezone.
- Your GoPro movies will *still* show time and date as local time and date of the shoot of the movie.
03-24-2019 01:30 PM
Thanks for the research. I, too, noticed this weird behavior by my GoPros including the Hero 7 Black. The EXIF data is saved with the date and timestamp of the current in-camera time, but it's stored as if it's UTC time.
In the case of us skiing recently in Utah (UTC-6 currently) it means that the camera's EXIF should show video that was shot at 10:00 A.M. Utah time (i.e., MDT) as being recorded at UTC 16:00, but it shows it as "UTC 10:00" which is wrong. Contrast this with an iPhone that does correctly show a 10:00 A.M. (MDT) video as "UTC 16:00" since the iPhone knows what time zone it's in.
I think your workaround of setting the computer's local time to UTC when batch renaming GoPro files makes sense. Too bad GoPro's firmware doesn't allow specification of time zone, which would avoid this weird error.