Use other apps

One of the big changes to Photos is the way in which it interacts with other apps. Although Photos now has improved editing tools, they still fall short of what you get in the likes of Photoshop and Pixelmator. But now you can use the Image > Edit With menu – which also available in the Ctrl-click context menu – to send your image to a third-party editor.

Changes made externally should be saved back to your library. They can be reverted by going into Photos’ editing mode and clicking Revert to Original. Test this with your preferred external editor on a copy first (Image > Duplicate), just in case.