Review by Klaus Schroiff, published August 2015

Introduction

The build quality of the Canon EF 11-24mm f/4 USM L is superb just as you would expect it from a Canon L lens in this price class. There's no wobbling whatsoever and the control rings operate smoothly. The lens is also designed to survive in harsh conditions with a sealing against dust and moisture. Fluorine coatings on the (immense) front and rear elements have been applied for reducing smears and fingerprints. The outer length of the lens remains constant thanks to the fixed lens hood although the inner lens tube moves a little according to the zoom setting. The front element does not rotate during focusing or zooming operations but this won't help you with filters because the (vulnerable) bulb-like front element just doesn't allow this. Conventional (front-)lens caps don't work either so the lens cap is attached to the lens hood. Honestly we would have wished for something more posh than a plastic front cap here but it does the job, of course.

The lens has a ring-type USM drive based on a front-focusing system resulting in an extremely fast AF speed. Typical for ring-type USM lenses full-time manual focusing is always possible in one-shot AF mode.