Hello all, I'm new to the world of photography. I just started with my first DSLR in March and now I'm trying to get more "serious" andi need some help. I have a rebel xs with a tamron 17-50mm 2.8 lens and I want something telephoto for outdoor shots. I'm going to a kite festival on sunday. the only problem is i'm poor so what's a better buy for $300? A used Canon EF 75-300mm f/4-5.6 IS USM or a Canon EF 70-200mm f/4L USM without IS Both are used on craigslist in good condition. I don't plan on going safari anytime soon, so i don't need the extra 100mm, but it would be nice to not have to hold the camera for long periods of time to get a sharp picture. I already tried the Canon 28-135mm USM IS and i didn't find it was worth the money. Any suggestions?