As usual it is time to spend a little on lens. I will be doing my first wedding event this May. I am a backup photographer; therefore, no risk involved. There is different light situation. There will be in door, church, park, and reception. Reading may advice, I came across this one. Canon EF 24-70mm f/2.8L USM Standard Zoom Lens for Canon SLR Cameras But the price seems a little out of reach ($1100). Is there any thing you can recommend that is comparable to this one. Meaning Sigma or other.