Slider height issue

Hello, I am having a very frustrating issue with my slider on my website . I am currently using the free version of the Enigma theme, I have a slider which contains three images.

My issue is that for some reason the height of the images changes for a brief second between transitions this causes the page content to move up and down every 3 seconds which is very annoying and off putting for the users.

Please take a look at the site in question ( http://2tec.club )

Can someone assist me?