There has been a lot of discussion about which lenses are sharp and how much difference there really is. The best way to check is to view your image at 100% and pixel peep. The following is from the sharpest zoom Canon currently makes the 70-200 f4L IS. You can see from the 100% blow up how good this lens is. I've owned all the 70-200 L's, the 100-400, the 24-105 f4L, the 17-40, and the 24-70 f2.8 and this one is just simply a cut above with prime like sharpness.