I really like the look of some of the outdoor flash photography that some of the members here are doing and I'd like to try this approach as well. I haven't used a hot shoe flash in years , so I'm completely clueless. The Fuji site has no meaningful info that I could find on the EF-42 and EF-20. Since many here are experienced with these type of flash units, could anyone explain the differences between the two? Big Thanks!