Just get one of those translucent quart-size (liter size for the imperial-measurement-challenged) plastic takeout containers with a snap-on lid. Cut a hole in the bottom or the lid (whichever fits better on your Metz) and slip it over the head of the flash. A little tape and/or Velcro to hold it on, and voila, instant Gary Fong for the cost of some cheap wonton soup.