Photo Gallery Opacity Transition - HTML CSS

HTML

<a href="#" target="_blank" class="opaque"><img src="example.png"/> </a>

CSS

.opaque{
opacity: .6;
-moz-transition: opacity 0.5s; /* Firefox 4 */
-webkit-transition: opacity 0.5s;/* Chrome */
-o-transition: opacity 0.5s; /* Opera */
}
.opaque:hover{
opacity: 1;
}

Example