Vantage Slider – image resolution

Hello,

I installed Meta Slider, and it works as well. The only problem is, that i used images of 1080px to 420px; but it seems like the theme or the slider would cut the pictures on the top and bottom.

http://www.f-koch-rennsport.de

Normally, the pictures are like that:

http://f-koch-rennsport.de/wp-content/uploads/2014/04/slider-4.jpg

How can i solve this?

regards