I take wedding and debut pictures and I have the Canon 430EX, on low lights especially on older churches, I find the 430EX does not have enough lighting power. My pictures come out yellowish. I set the white balance on my Canon 350D to Flash setting. Would upgrading to 580EX solve my problem? BTW, I use a Canon 28-200mm f/3.5-5.6 EF USM lens.