I do want the size of the image and type to be constrained by the size of the wrap DIV as to accommodate the nav bar and some padding around the content. changing the wrap height to 100vh does this.
I have tried the DIV with a background image but as you can see here the issue with that is that you have to set the DIV to 100% width and height, as the size of the background image is driven by the size of the DIV and no the other way around. This pushes the blue text down to the bottom of the wrap [first image]. where as I would like the blue text to sit just under the big type image. [second image]
Thanks for your input Andy!