CSS3 fade opacity fast

/* from: http://bavotasan.com/2011/a-simple-fade-with-css3/ */
.fade {
    opacity: 1;
    transition: opacity .25s ease-in-out;
    -moz-transition: opacity .25s ease-in-out;
    -webkit-transition: opacity .25s ease-in-out;
}

.fade:hover {
    opacity: 0.5;
}

/*
usage:
<img src="http://bavotasan.com/wp-content/uploads/2011/09/fadeimage.jpg" alt="" width="200" height="150" class="fade" />
*/