SOURCE

<div class="a-text">1</div>
<div class="a-img1">2</div>
<div class="a-text">3</div>
<div class="a-img2">4</div>
<div class="a-text">5</div>
<div class="a-img3">6</div>
<div class="a-text">7</div>

div{
    height: 100vh;
    background: rgba(0,0,0,.7);
    color:#fff;
    line-height: 100vh;
    text-align: center;
    font-size: 20vh
}
.a-img1{
    background-image: url(https://images.pexels.com/photos/1097491/pexels-photo-1097491.jpeg);
    background-attachment: fixed;
    background-size: cover;
    background-position: center center;
}
.a-img2{
    background-image: url(https://images.pexels.com/photos/2437299/pexels-photo-2437299.jpeg);
    background-attachment: fixed;
    background-size: cover;
    background-position: center center;
}
.a-img3{
    background-image: url(https://images.pexels.com/photos/1005417/pexels-photo-1005417.jpeg);
    background-attachment: fixed;
    background-size: cover;
    background-position: center center;
}