I have a jumbotron with a picture behind it, when I have the picture on a medium screen it shows the full picture, if I go to a large screen it loses part of the picture and if I go to phone size the picture only shows the left side of it. I have tried fluid etc. to no avail, how do I make the picture show fully on all formats. I have worked via the tutorial that shows the bakery site. Thanks in advance.

Try changing the background size property from "cover" to "contain"

Will give that a go, thanks for your response.

unfortunately that doesn`t work, it reduces the picture to half the screen ???