The 580 EX/EX II or the 430 EX? I will be investing in a flash in the next few months, I hope, and having next to 0 experience with any flashes other than my own Sunpak Auto 144 D. My flash was made for film, it is 3rd party, and it had NO auto features on any camera I have ever used it with. I had a nice flash with the Oly I had way back when, but I never really had much chance to use it. So, enough background. I would be using the flash mainly for close up nature, and people. Shots like these... I would eventually like to use the flash along with another/others in a master slave combo for my fish photography, but that is a future concern. The issue here is the two I mentioned above. I am not adverse to buying the 580ex or the ex II, but the 430 is way more in my price range. Power only has to be good enough for close up work and portraits. The fish stuff counts as close up. The camera and lenses I have are the 30D, EF 70-200 f/4L, EF 50mm 1.8, Sigma 17-35mm 2.8-4 EX, and I am looking into The Sigma 10-20mm 4-5.6 EX. This is my situation. Advise would be great! Thanks!