I just got put in charge of taking photos of a construction company's buildings for their website and catalogue, yet when doing some run throughs in a building with the owner I noticed that no matter how far back I was in some small rooms I still needed to capture more, right now I have a canon 20D with a 17-85mm AF/IS lens and I was seeing if there is a step down filter or even another lens that will capture more of these rooms, if there is anything I can get I need to know soon because I need to take more shots for them in a week, I really appreciate it!