Modal without fade transition has opaque black backdrop

Created by: AREALFAKE

When I open a modal window on Bootstrap 3 the backdrop of the rest of the page becomes black (or very dark grey). I found that the modal-backdrop was responsible for this as it didn't have an opacity set.

I used the simplest example with opening a modal window through the use of

<a data-toggle="modal" href="#" data-target="#modal-1">open</a>

referring to my model with id modal-1 on the same page.

.modal-backdrop {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 1030;
  background-color: #333333;
  opacity:0.8; // I ADDED THIS LINE 
    }
}

Maybe it is intential to have a dark full color backdrop, but it looks crappy and takes away the visibility of the drop shadows of the modal itself.