I'm thinking of getting a wide angle lens for my Olympus C730 but I don't know which one to get. Is a .45x or .43x wider than a .70. I think I saw a .70 from Olympus but it's sort of big. Any suggestion on what to look for or avoid. I guess any of the leading brands are good but is Kenko okay? Also looking for something that doesn't cost an arm and a leg. I've also seen one that has serious vignetting happening.