I'm looking to take some indoor architectural shots for a friend of mine. I've wanted to get a Ultra Wide angle lens for awhile now and this is just the excuse I need with my wife. However, what would be a great wide lens that I could possibly use on both my 7D and 5D? I'm covered from the 17-300mm range with pretty good glass for the 7D but only 24-300mm with the 5D.
Any suggestions would help immensely.
My budget would be up to....$1000. But I'm guessing this might not be a lens I use all that often so I'd like to keep it on the cheaper side if possible I'd like to spend $500-$600 on a used lens if possible. I'm also saving for a 5DII, so keeping some money in reserve would be great.