My 77mm reversal ring arrived today so I decided to test it out w/ the 17-40 reversed. A few globs of honey attracted about a hundred ants within minutes. They sure love honey!
All shot at 17mm, f11 or f16, and two 580ex's.. one on a stand with stofen and one handheld with lumiquest softbox.
Yeah, it's pretty fun. The working distance is better than a 100/50 coupled and it's easier to wield, though It's pretty challenging to tell when something's in focus when you're looking through the lens at f16.