This test scene is a tough backdrop and will expose shading/light fall-off performance of any lens real quick. But the short of it is that the Tokina is a much stronger performer than the Canon in light fall-off. Aperture for aperture, the Canon never matches the Tokie. The Tokina 11-16 is one of the very best shading performers I've tested to date in the UWA category. In fact, IMO it *is the best* in this category.