Visual Composer

Programming novice here. I'm editing a WP site already constructed using visual composer, but having trouble creating responsive elements.

Can anyone point me in the right direction as there's little out there in the way of guides.

Problem: I'm trying to use the default image carousel as a large header image(s). I can get one to sit in a new row, but the images contained are sticking to their original dimensions (1200x700), with no responsive resizing.

The row is 'stretch row and content no padding), how can I make it's carousel content stretch 100% by width? Ive tried with a single image with similar results :(

Any help would be gratefully received.

Thanks.

via Chebli Mohamed