@yanta Thanks for taking the time to test this.
I’ve kinda given up and accepted that my chosen wallpaper is somewhat aggressively zoomed.
The thing is; this was something that happened with an Opera update – I’ve used exactly the same wallpaper file on exactly the same monitor and settings for two years. It used to look nice and now it’s cropped, including in full screen mode.
WIN10-64. Opera 57.0.3098.91 Norwegian. HWA On.