title: Set page background image opacity
body: <p>How to set background image for entire page opacity to 0.4 ?</p>
  
  <p>I tried with </p>
  
  <pre><code>html { 
    background: url(img01.jpg) no-repeat center center fixed;
    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
  
     opacity: 0.4;
     filter: alpha(opacity=40); /* For IE8 and earlier */
  }
  </code></pre>
  
  <p>but it set all element's on page opacity and i only want opacity of img01.jpg ??</p>