Last shot with my Canon EF 17-40mm f/4 L lens before I sell it. I took it out today to do some test shots (brick wall) to put in the ad. I have never been happy with this lens (this is my second copy). The center of the image is nice and sharp but the corners are soft. They do get better when you stop down, but I have to go all the way to f/16 before I get an acceptable result from it.
