I've seen how to customise the background of the login window on OS X 10.10 and 10.11 using /Library/Caches/com.apple.desktop.admin.png, but what I'd like to know is how to figure out where on the image the overlaid elements like the login fields, banner text and restart/shutdown buttons appear?
This would allow me to modify the image I want to use so that these will be more easily visible.
Dan Jackson (Lead ITServices Technician)
Long Road Sixth Form College
I don't have the .PSD anymore but here's a .PNG i used to define the safe area - the size of those elements doesn't change based on screen resolution, but the user icons & name/password field are always centered and the three power buttons are always the same relative distance from the bottom edge: