Hey everyone. I am in need of a canon 70-200mm lens. The only question i have is should i get the 2.8 or the 4 apeture. I absolutely need it for the paris airshow this summer and I am also a sports photographer. Like i said in the subject, I own a digital rebel. I think i would be perfectly fine with the f/4 L but i don't want to regret it later. Another thing, the canon lenses seem to retain their value longer so there is a chace that a year down the road, i could sell it for close to the price i bought it for and get the f/2.8 if i have a real need for it. I'd really like to hear what you guys have to say about the two lenses. Thanks!