It’s only natural to be curious about the piece Canon calls Diffusion Plate. It’s the same reaction I received when I first used the original Gary Fong Lightsphere II. Some even laughed at the “Tupperware” but silly as it may seem, the product [Lightsphere] went on to become one of the world’s most popular and effective light modifiers. So here you have the Diffusion Plate which Canon cautions against scratching the surface or else flash light may not diffuse properly. The examples below clearly shows the exposure difference with and without the plate. I started a thread on dpreview with images for anyone interested in the G11 underwater case.