Canon’s 580 EXII is the newest in their line of ETTL-II enabled flashes, and it’s a serious contender for their best flash yet.
Building upon the success of the 580 EX, an almost universally loved flash, Canon has taken the 580 and beefed it up, improving upon the original’s design in a few clever ways. First, in keeping with the theme of the new 1D Mark III, they have added rubber sealing around all of the joints and openings on the flash, adding the “water resistant” tag to the basic features of the flash. The new descending locking boot allows the rubber base of the flash to meet up with the top of the Mark III and presumably future Canon bodies, creating a relatively waterproof seal. A new metal hot-shoe adds to the ruggedness of the design.