Speed of Fading Between Banner Images

Hi,
I'm setiing up a website in 7.1 and would like to have three full width banner images on my homepage transitioning. The images must fade and they must FADE SLOWLY. Currently when I set the transition to autoplay and fade (in a slideshow gallery) the movment between images is too abrupt and doesn't really fade at all. How can this be achieved using code? It's 7.1 and it's the homepage's banner pics that I'm looking at (or a slideshow gallery as banner pics I guess?). I can see from past forums online (pre SS 7.1) that people have used code to slow the fading down between images but the solutions are not geared towards a homepage and I can't see where I can inject code to a banner pic - any help much appreciated, thanks.

Ridiculous that this is not adjustable. Seems so basic. The fade transition is so fast that it's hardly noticeable. If it's a full screen slider, this is highly annoying – too abrupt! Just contacted help and it's not possible. Every free JS slider plugin out there has that option. Really? 

Try this fix:

.gallery-fullscreen-slideshow-item-img{
	transition: opacity 1600ms ease-in-out !important;
	-webkit-transition: opacity 1600ms ease-in-out !important;
	-ms-transition: opacity 1600ms ease-in-out !important;
	-moz-transition: opacity 1600ms ease-in-out !important;
	-o-transition: opacity 1600ms ease-in-out !important;
}

.gallery-fullscreen-slideshow[data-transition="fade"] .gallery-fullscreen-slideshow-item[data-active="true"] .gallery-fullscreen-slideshow-item-src{
	transition: opacity 1400ms ease-in-out !important;
	-webkit-transition: opacity 1400ms ease-in-out !important;
	-ms-transition: opacity 1400ms ease-in-out !important;
	-moz-transition: opacity 1400ms ease-in-out !important;
	-o-transition: opacity 1400ms ease-in-out !important;
}