"F12 for standard screenshots to Steam folder.
F8 for debug screenshots (with map co-ordinates and settings info).
F10 for Hi-Def screenshots no HUD, saved to desktop ."
Yep, I've already run into a couple. Learned the hard way to not travel through them when you're so overencumbered that you can't sprint (I was on the easiest difficulty in story mode, so it didn't really hurt me. It was just SO SLOW)
Just wait until you get some Aurora nights from a nice vista.
If you're like many of us, you're going to end up with a lot of "wallpapers".