Ultra-Wide Zoom. With 126° of coverage at 11mm, the 11-24mm f/4L is Canon’s widest rectilinear zoom lens. This ultra-wide’s extremely high image quality with minimal distortion makes it a perfect choice for landscape and architectural photography. It covers the ultra-wide to moderately wide focal lengths and has constant f/4 aperture throughout the zoom range.

Full-Frame Coverage. The ultra-wide angle zoom offers 35mm full-frame coverage, making it compatible with Canon’s full line of EF-mount DSLRs. When mounted to a crop-frame APS-C camera, it offers a 17.6-38.4mm equivalent focal length.

Ultrasonic Motor. This internal focusing lens utilizes a ring-type Ultrasonic Motor (USM) for fast, near-silent performance for both still and video use. It’s full-time manual for quick tweaks on the go, and the dedicated AF/MF switch allows you to disengage autofocus entirely when desired.

L-Series Quality. As part of the L-series, image and build quality are premium. The 11-24mm f/4L does not disappoint. It features four aspheric, one ultra low-dispersion, and one “super” ultra low-dispersion lens elements that effectively correct barrel distortion while reducing chromatic aberrations from corner to corner throughout the zoom range. It has fluorine coatings on external elements and subwavelength coatings on the internal elements to minimize image quality-robbing flare and ghosting. The weather-sealed lens barrel provides protection from the elements, with the fluorine coatings doing double-time by repelling dust and fingerprints.

Built-In Hood. Do note that the lens hood is built into the lens barrel, so there’s no taking it off. This also means there’s no threaded filter ring. However, the lens does accept rear gel filters.

• You can only use rear gel filters with this lens because its hood is built into its barrel.

https://blog.lensprotogo.com/2016/02/08/4-lenses-to-spice-up-your-wedding-photography/