Hello fellow photographers! I think I've caught the lens bug once again. It's been a while since I've bought anything camera related, but I've been looking at L lenses. I currently have a Canon 50D and it came with a 28-135mm lens and I bought a 70-300mm lens. I'm going to the camera store where my uncle works on Saturday to try out some lenses on my camera, but I'm undecided about whether I'd like to go with a macro lens (which is considerably cheaper) or a longer range telephoto lens. I've been looking at the 100-400mm L lens, but there is also a 400mm f5.6 L lens which is about the same price. I would mostly be using the lens for the reach at 400mm to get birds, but I'm thinking the 100-400mm would give me more options. Can anyone give me some good advice about this? The $1700 price tag is a bit daunting, but the more I look at pictures, the more I would like to get a better (and more professional) type of lens.