Excellent quality. Great effects with this lens also.

After reading the review, I am a bit surprised by some of the findings so I wanted to comment on my real-world use. First of all, the lens is expensive, but not in relation to the unique shots you can take and in comparison to Canon's long lenses.

Very sharp in center, very good sharpness until the furthest corners; Low CA, manageable vignetting, great build quality, very good flare resistance; The shots at 11mm are very difficult to do well, but are amazing when they come together

Large; heavy; no simple way to use filters; expensive

"This lens is amazing. A true rectilinear wide angle zoom covering 11mm to 24mm on a full frame sensor. Not a lot of point on a crop sensor, there are less expensive options that provide the same coverage, but for full frame this lens is a killer. Know that it is big and heavy.

Canon's latest additions to the ultra-wide arena have been impressive. The Canon TS-E 17mm f/4 L is awesome and the EF 16-35mm f/4 USM L IS is best in class. So is Canon's mojo sufficient to deliver greatness with the Canon EF 11-24mm f/4 USM L once more ... even on the EOS 5Ds R ?

Expensive, but well worth it, great optical quality and heavy as hell especially with a 1 series body

Durable; Great Features; Great Picture Quality

Heavy

This new ultra-wide angle zoom lens is currently the widest rectilinear lens available for full frame SLR cameras. It sports a reasonable f/4 aperture throughout the zoom range, silent Ultrasonic focusing, with full time manual override and a weather resistant build.

The Canon EF 11-24mm f/4 L USM lens is large, heavy and it doesn't take regular filters, but what it gives you is a uniquely (and extremely) wide point of view that would otherwise require stitching of several shots to achieve.

There has been much anticipation surrounding this new Canon L-Series wide angle. This lens is perfect for landscapes and cityscapes, and even night/star trail photography. The fact that it is an professional L-series lens means that imperfections like chromatic aberration and curvilinear distortion...

The Canon EF 11-24mm f/4L USM is a unique ultra-wide-angle zoom lens that's very capable but also very pricey indeed. Ideal for landscape and architectural photographers looking for an all-in-one zoom that can also give them a competitive edge thanks to the 11mm focal length, the Canon EF 11-24mm...

This new ultra-wide angle zoom lens is currently the widest rectilinear lens available for full frame SLR cameras. It sports a reasonable f/4 aperture throughout the zoom range, silent Ultrasonic focusing, with full time manual override and a weather resistant build.

Outstanding optical performance; Unique 11mm focal length; Excellent build quality; Reasonably low distortion; Fast autofocus; Dust and moisture resistance

Slight wave to distortion pattern; Large and heavy due to optical design