Naturally many readers will also wish to compare this lens with Nikon's AF-S 18-200mm F3.5-5.6 VR, but as might be expected there's really no clear-cut winner (indeed perhaps the more interesting comparison lies in the different compromises the two manufacturers have made in their designs). In terms of sharpness, the Nikon is better at 18mm, but the Canon wins at 200mm, and also shows a less catastrophic drop in performance in the 135mm region. The Canon generally exhibits a tad more chromatic aberration all round, and has higher barrel distortion at wideangle, but less pincushion distortion at 50mm. And while the Nikon has a superior autofocus system, the Canon fights back with its highly impressive image stabilizer. So the two essentially match each other punch-for-punch, with neither quite able to deliver a decisive knockout blow.