Hero-image

I have a question regarding the image on the front page. In the template it takes the whole space of the site, however I wwould like it to be centered but with space around it so that it can resize with the viewpoint/window size. I currently went the rout to create an image with the borders around it in Photoshop and put it in the header media. Since I was able to get the website live, here is the link: HPC-Fotografie Is it possible to put the abstract image in a box that does not fill the whole front page? Thanks in advance. Kind regards, Max