Right now I have a Canon Digital Rebel XTi and I am using the kit lens, but I have already outgrown it and would like to get a new lens. Since I sometimes shoot some animals that are in motion I decided that I wanted a fast lens. However my budget is rather limiting, I will only have a $400 budget when I get my paycheck in a week. One other thing I want to be able to do is zoom close to the subject so I can get some close up shots, I can't do that with my current lens. The lens that I'm looking at getting right now is the Tamron 28-75mm f2.8 XR Di LD, that will take up all of my budget. But two weeks after that I will have enough to get a set of Kenko extension tubes, so that would allow me to get closer pictures of the subject. I have heard good things about the lens I am looking at and how it is even as good as the Canon L series lens, so that was swaying me towards getting it. But I want some advice from the great photographers here.