Slider problems

Hi!
On my site http://www.mediakusten/testsida I have a huge problem with the slider.
No matter what image-rate I have 1 or 2.9 or whatever the slider gets to thin. Am I looking at this the wrong way? Change by css or pictureproblem or?

My goal is that the image is like 700 px height.
I have read some solutions but can’t get this to work and I’m using a child theme.

Please help! I’m pulling my hair and I’m soon out of hair.

//Patrik