I was trying to put together a relatively cheap fs100 kit, but you know how the best laid plans of mice and men go. So I primarily work in documentary and I loved the 5d with the 24-70 2.8 lens. My goal is to be able to go as wide as possible but I also need a little range. I recently bought the sigma 17-50 2.8 which is producing a nice image, but I still would prefer it to be even wider. Any suggestions? Or curious what other people are using for there go to doc lens.