html,
body {
    height: 100%;
}
header.carousel {
    height: 500px;
    max-height: 500px;
}

header.carousel .item,
header.carousel .item.active,
header.carousel .carousel-inner {
    height: 100%;
}

header.carousel .fill {
    width: 100%;
    height: 100%;
    background-position: center;
    background-size: cover;
}