<style>
   .img-texto {
    position: relative;
    float: left;
   }
   .img-texto span {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: 999;
    background: #848282;
    padding: 60px;
    color: #fff;
    font-family: sans-serif;
    opacity:0.8;
    font-size: 20px;
    }

</style>

    <div class="img-texto">
    <img src="img/img1.png" alt="" height="900" width="670" />
    <span>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco</span>
    </div>
    <div class="img-texto">
    <img src="img/img2.png" alt="" height="900" width="670" />
    <span>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco</span>
    </div>