The Image of the Month for March 2013 is this high-speed flash image of a pair of eggs shot with an air rifle pellet.  Flash duration 9-microseconds, 50mm prime Canon lens on a Canon 5D MkII in the open-flash mode.  The image is blurred around the extreme edges and this was found to be due to the protective U.V. filter I had fitted to the lens to prevent it being splattered by egg.  I found no blurring in earlier HSF shots taken using the same kit – but without the U.V. filter.  Live and learn.