Full Width Featured Image on Home Page

I would like to place a full-width image at the top of my home page, but the content should remain less than full width

I've looked several entries in the forum, but they all seem geared towards the header module that pre-dated the entries module.

I've tried to use the entry module and the Hero option, but the amount of the image shown seems to depend on screen size (decreasing width of screen increases height of image, and increasing screen width decreases image height). I would like the amount of the image being displayed to remain constant regardless of screen size

I've tried using the featured image option, but can't get it to go full width

Thanks