Header Background Size

Hello BlueOwl Team,

I am using Fortuna Theme. But when i use header images its becoming very large (like http://blueowlcreative.com/wp/fortuna/contact-custom/ ). What i needed is a header image with a height like as on your theme ‘Savia’ (ref. http://blueowlcreative.com/wp/savia/about-us/ ) ie; the image below “Create your own Headers
We are a passionate about WordPress bunch of fellas that take pride in their work“. Can you please help to adjust all the header backgrounds with that size.