Thanks so much for your very quick reply
aha yes I can see that works - but only if the .fullscreen class is being applied
Apologies - I forgot to mention that I had taken the fullscreen class off the section and set a height for the slider...the code I am trying to use is:
<section id="slider" class="slider-parallax swiper_wrapper clearfix" data-loop="true" style="height: 700px;">
however if I remove the slider-parallax class ie:
<section id="slider" class="swiper_wrapper clearfix" data-loop="true" style="height: 700px;">
more than half of my image is "hidden" - please see attachemnt
Any further ideas much appreciated