Default background on login screen

[CLS7]

When I boot my iMac 27 "(late 2015) with Mac OS Mojave PB 4 and get to the login screen, I have a default background (Mojave dessert background)

I have upgraded from High Sierra where the login screen had the same background as my desktop background.

How do I change this in Mojave? I want the same background in the login screen as I have on my desktop. Anyone who can help me how to do?

 

[fisherking]

i tried to sort that out, and wound up with a black screen until the login (when my chosen wallpaper showed up); right now, apple seems insistent that we use their default for booting up.

just a guess, but you could (carefully! and save the original) try changing "Mojave.heic" in the Desktop pictures folder... with a same-named .heic file. somewhere, i screwed that up (and hence, black screen).

pb4 has me back in business!