I am putting up a house for rent soon and need a few pics for advertising. The widest lens I have is the 12-50 and Samyang 7.5 fisheye. Location is in Perth Australia so the rooms and house are not shoebox sized as in other countries. I have been lusting after the 12-40 PRO and wondering if that will be wide enough or spend similar money on the 9-18, which I won't use in general. what do you all think?