With OS X 10.10.3 Apple introduced the new application Photos. Photos internally uses a database where the GPS coordinates of the photos are stored. In this regard, Photos works similar to iPhoto or Aperture. If a place has already been assigned, then a small location symbol is shown in the lower left corner of a photo. If you open the Info window then the location is displayed on a map.
Photos 2.0 in macOS 10.12 Sierra
Beginning with Photos 2.0 that is part of macOS 10.12 Sierra Apple provides an interface for other apps to set the GPS location of photos. myTracks 3.1 and newer supports this interface and provides an easy to use workflow. To geotag photos you first have to select the photos in Photos. Next switch to myTracks and select Import from 'Photos' app... from the File menu. myTracks will add the photos to the Pool of Photos. You can use the Pool of Photos as explained in the corresponding documentation.
However, photos from Photos cannot be assigned to a track in myTracks. But you have to use the GeoTag buttons in the Pool of Photos. By pressing the GeoTag button the GPS location will directly be written to Photos. There is no need to refresh anything in Photos.
Older Photos releases
Previous versions of Photos do not provide a way to set the place of a photo after the photo has been imported.
Therefore, there are currently two ways myTracks can be used with these versions:
- Geotagging before import: If you download your photos from your camera to your Mac, then you should not import directly into Photos, but first put the files in your local file system. Now perform the geotagging with myTracks, so that the GPS coordinates are written to the files. Then import the files in Photos.
- Export/Import: If you already have the photos in Photos, then there is no other way than exporting the photos from Photos first, removing the photos from Photos, performing the geotagging on the exported files and finally importing them back again to Photos. The export of the photos may result in a change of the quality of the photos because the are re-rendered during export. Therefore, the first workflow is to be preferred.
I download my photos always using Adobe Lightroom, because I do the RAW processing there. From Lightroom I export the photos as JPG files. Then I perform the geotagging of the JPG files using myTracks. Finally, I import the files in Photos.
I hope that in the future Apple will provide other way of modifying the GPS coordinates of imported photos even after importing the files into Photos.