so ive been learning a lot about photography with my xti and kit lens and damn its fun i want to know what OT thinks; My overall plan is to acquire good lenses over time. I would like a nice zoom lens in the 10-22mm range, 24-70 range, and in the 70-200 range. I think im gonna buy it in order of 70-200 first, 24-70 second (to replace the kit lens), and 10-22 last. I find myself needing to go past the kit lens' 55mm limit more and more, which is why i want to get the 70-200 first. I can put up with the kit lens for a little longer while i save up for a nice 24-70. so basically i think ive narrowed it down to either the: 1. Canon EF 70-200mm f/4L USM http://www.prestigecamera.com/product.asp?id=cn70200usm&l=Pricescan or, 2. Sigma 70-200mm f/2.8 EX DG APO MACRO HSM http://www.bhphotovideo.com/c/product/435163-USA/Sigma_569101_70_200mm_f_2_8_EX_DG.html with the canon being $534 and the sigma being $889. my question is, is the sigma worth the extra $350? $889 is kinda more than i wanted to spend any suggestions? comments? recommendations? all are welcome edit: in case anyone asks, the most common things i usually photograph are city/landscapes, action scenes such as fires, unique police activity(my scanner tells me where all this stuff is), and track races, cars, hotrods, etc. I also do a fair amount of night shooting. I think the 70-200 would mostly be used for fires, police activity, and track races. the 24-70 would be used for taking pictures of cars and the city and landscapes.