On this page you can see the widest FL setting and FOV for each lens (all at infinity focus). It might help to use the tall pole on the left side when judging between the 16-17mm lenses. B is clearly the widest of the standard zooms at 16mm, and C is slightly narrower at 17mm. But what is interesting is that D (the Canon 17-55 IS) is not as wide at its 17mm as C (Tamron 17-50) is at its 17mm mark. E and F are basically identical at 18mm, and of course, the Canon 24-105 (G) is narrowest at 24mm.