Inner page hero size

Sinse the last update my inner page hero has been compleatly wrong cropping. the accual image is way to big and blurry too. i tried several thinks to fix it but i cant get it to work. is there a way to put inner page hero height to like 15%?

im compleatly lost here and i need help! and explain it to me like im a shimp… im a totaly newbe with wordpress.

The page I need help with: [log in to see the link]