Background image on only presentation page

I’m loving the Tempera theme! It’s great for my site and for clients I am building sites for.
My question is how can I get my background image to show up only on my presentation page and with the “Content” section remaining transparent on only the presentation page? Right now my background image and the need for the content page to be transparent on the presentation page, is carrying through to every page and post on the site. Just too much for reading the text and I’d like to fix that.
Thank you so much for any help!