Yeah, just an image on a canvas. It’s weird to use 1920x1080, but it works for all viewport sizes; though, it doesn’t hit the right & bottom borders unless the aspect ratio is the same.
Yeah, but I tested the same thing with a widget, too, and it worked (I kept the image at (0,0) in the widget); an image is a widget, also, so they both work the same, so you just need to get the widget itself, not anything inside it. Alignment is the pivot point of the widget, which is the origin of it, so setting it to (0.5, 0.5) moves the origin to the center of it.
As for which to use (canvas slot position or render transform translation), the canvas slot position sets the position of the widget directly, whereas the render transform translation offsets the widget from its location, so render transform translation only works if the widget is at (0,0).
This is what the widget looks like:
Also, I noticed you’re on UE5. I’m on 4.20, but that shouldn’t make a difference.