.bgimg {
    background-image: url(http://img08.deviantart.net/4c8b/i/2013/022/0/a/speedcubing_by_linkinkoowna-d5sbo58.jpg);
    background-position: top center;
    background-repeat: no-repeat;
    background-attachment: fixed;
    position: absolute;
    top: 0;
    width: 100%;
    height: 750px;
    z-index: -1;
    opacity: 0.7;
}

.bgimg-1 {
    background-image: url(http://img08.deviantart.net/4c8b/i/2013/022/0/a/speedcubing_by_linkinkoowna-d5sbo58.jpg);
}
.bgimg-2 {
    background-image: url(chuj.jpg);
}