Vertically Centered Text on a Full Sized BG Image

centeredTextFullBG.sass

@mixin image-spacer($ar: 1.00, $max-height: 600px, $min-height: 0, $container-width: 1.00) {
  
  @if $min-height <= 1.00 and $min-height > 0 {
    $container-width: $min-height;
    $min-height: 0;
  }
  
  &:before {
    content: '';
    display: inline-block;
    padding-top: $ar * 100%;
    vertical-align: middle;
  }
  
  @media (min-width: ($max-height / ($container-width * $ar))) {
    height: $max-height;
    
    &:before {
      padding-top: 0;
      height: 100%;
    }
  }
    
  @media (max-width: ($min-height / ($container-width * $ar))) {
    height: $min-height;
    
    &:before {
      padding-top: 0;
      height: 100%;
    }
  }
}
// Usage:
.my-module {
  @include image-spacer(.665, 450px);
  
  background: url('http://c3.staticflickr.com/7/6002/5959488791_f126825d38_b.jpg') no-repeat center center;
  background-size: cover;
  text-align: center;

  .my-module-content {
    display: inline-block;
    position: relative;
    width: 75%;
    vertical-align: middle;
    z-index: 10;
  
    h1 {
      color: #fff;
    }
    
    h3 {
      color: #fff;
    }
  }
}