title: Can I set background image and opacity in the same property?
body: <p>I can see in CSS references <a href="http://www.w3schools.com/css/css_image_transparency.asp" rel="noreferrer">how to set image transparency</a> and <a href="http://www.w3schools.com/css/css_background.asp" rel="noreferrer">how to set a background image</a>. But how can I combine these two in order to set a transparent background image?</p>
  
  <p>I have an image that I'd like to use as a background, but it is too bright - I'd like to turn the opacity down to about 0.2. How can I do this?</p>
  
  <pre class="lang-css prettyprint-override"><code>#main {
      background-image: url(/wp-content/uploads/2010/11/tandem.jpg); 
  }
  </code></pre>