title: Add Opacity to Part of an Image (CSS)
body: <p>How can one add opacitiy to just the left <code>100px</code> of a <code>600px</code> wide image in css? Is there a <code>css</code> property for that?</p>
  
  <p>I have tried to add an overlapping <code>div</code> and add opacity to this <code>div</code>, but that is a pain in the back and does not look as a good solution. </p>